Old Rock Day – January 7

This day is set aside (though no one knows how long it has been observed or when it was first celebrated), to consider how old the Earth is and how it has shaped our lives. It’s also a shout-out to some of the earliest geologists like the Theophrathes, Pliny the Elder, Ulisse Aldovandi, James Hutton and William Smith.

National Jewel Day – March 13

This special day is set aside to appreciate precious stones and jewelry. From the earliest examples of stone, bone, and shell jewelry, to the most lavish and intricate designs of today, National Jewel Day is meant to recognize them all. Those who choose to participate are encouraged to wear their most spectacular bejeweled pieces and take the occasion to gift jewelry to those important people in their life.

Geologists Day – April 7

This day is dedicated to those folks who make it their life’s work to explore, research and disseminate their knowledge of rocks and Earth’s history. It is also the time to appreciate all of those things in our lives that we have or know because of geologists. This includes such daily used items as toothpaste and even cell phones. Younger folks contemplating a career in geology can take this opportunity to discuss with practitioners in the field, what the job is actually like.

Earth Day – April 22

You can’t get any “Earthier” than rocks, gems and minerals. This is a day for rockhounds to explore and to appreciate Earth’s treasures.

Nickel Day – May 16

Devoted to the mined element, nickel, this day was created to acknowledge this important metal. Nickel has been used by humans for at least 2,000 years. By the middle of the 19th century, it was ubiquitous in American coinage as well as that of other European nations.

Dinosaur Days – May 15 & June 1

Dinosaurs lived millions of years ago, but they’re top of mind today. So much is still unknown about these fascinating creatures. Celebrate what we know and anticipate what we don’t on this fun day for young and old alike.

National Caves & Karst Day – June 6

This day is dedicated to the majesty and importance of these amazing rock formations. Most people know what caves are, but few are familiar with “karst” landscapes. A karst landscape is characterized by rocky hills, aquifers, springs, sinkholes and caves. Hundreds of different minerals and gems are found in caves, and 40 percent of drinking water in the U.S. comes from karst aquifers.

World Oceans Day – June 8

Beach finds from shells to rocks, minerals and sea glass are a favorite. Celebrate the oceans that bring us this bounty.

International Drop a Rock Day – July 3

This a day for having a bit of fun while inspiring kindness toward others. Across the world, individuals, families, and groups of all types get creative and paint rocks with pictures, themed messages, or even advertising and hide them. Anyone can try to find them. When they are found, the lucky holder of that rock can keep it, hide it again, or if it is part of a local promotion, contact the sponsoring group. This highly popular activity is not restricted to International Drop a Rock Day; many groups do this throughout the year and hold rock-painting parties before going out and hiding them.

International Rock Day – July 13

Sometimes referred to as World Rock Day, this day is intended to celebrate and to contemplate the importance of rocks to humankind. It is to honor the rock as one of the most fundamental aspects of human survival. If there is one day per year to give rocks their due, this is it!

National Pet Rock Day – September 1

This tongue-in-cheek holiday is dedicated to the 1975 marketing scheme that led to the sale of over one million pet rocks. On this day, many people “adopt” a pet rock at functions planned to celebrate this phenomenon.

Collect Rocks Day – September 16

Held since 2015, Collect Rocks Day celebrates all of the diverse types of rocks and all of the different places they can be collected, no matter where in the world you live. It is a celebration of Earth and geology for everyone.

National Fossil Day – October 16

As the name implies, this day is reserved for appreciating and exploring fossils. Of the approximately 250,000 different fossilized species that have been identified, it is estimated there are millions more to be found. Many groups organize fossil hunts and expeditions on this day in early fall. Be sure to find one near you.

This story about rockhound holidays appeared in Rock & Gem magazine. Click here to subscribe. Original story by Chris Bond. Updated yearly to reflect current dates and holidays. 

The post 2024 Rockhound Holidays first appeared on Rock & Gem Magazine.

The Impact of Light

Light is a major component of art and craft. Light is what reflects and allows us to see shape, color and the subtleties that the hand and eye created. However, the lapidary who facets (the process of turning the rough gem crystal material into a decorative gemstone) a stone has to consider light in another dimension. Light is an essential part of the medium and process, just like paint is essential to painting a portrait.

Light and the gemstone’s material are married in the creation of a jewel. Light reflects off the gemstone surface and returns to your eye like any craft or art. However, how to cut gemstones properly involves light also entering the gemstone and bouncing around, and returning from inside the gemstone. The greater quantity of light that can be captured and moved within the gemstone, the more exciting the jewel becomes. Poorly cut facet angles will allow the light to simply pass through the gemstone making a window. Correct angle facets can also be cut to break up the returning light, creating scintillation. Now, the gem sparkles! The attention given to light is a major difference between mass-produced faceted colored gemstones and performance-faceted colored gemstones cut by lapidary artists.

Learning to Work With Light

Gaining knowledge, as well as understanding and learning how to cut gemstones to apply it to faceting is complex and takes time. Like playing an instrument or learning to dance, the key element to success is practice. Through practice, artists begin to see the results of their efforts and understand the effects of subtle changes and modifications. With this knowledge and experience, a lapidary can then start to develop new and better techniques to improve a jewel’s performance.

When designing and faceting a gemstone, a designer has to consider and make decisions regarding the different performance attributes of the stone that result from various cutting techniques. These attributes include the following.

• Color depends on how to cut gemstones to enhance their natural color, resulting in a variety of saturations, hues and transparencies.

• Brightness is perceived when light enters the stone, bounces around and reflects back to the viewer’s eyes.

• Scintillation comes from different facets and their ability to create different beams of light that make a sparkling effect.

• Dispersion of light creates secondary and tertiary colors and is made by creating angles that separate the colors of the light spectrum.

• The darkness or lightness of a gemstone is determined both by how to cut gemstones using faceting angles and the depth of the cuts to darken or lighten the stone and ultimately affect the jewel’s weight.

Everything All at Once?

In a perfect world, artists try to maximize all of the performance attributes of a finished jewel. However, it is a balancing act because enhancing one performance aspect of a jewel means another may suffer. Making a stone lighter in color and also maximizing its weight by making it larger doesn’t necessarily work together.

The different attributes of light performance must be balanced and work together to create the best outcome for the jewel. These trade-offs are usually driven by the buyer. Lapidaries must consider the capabilities of each individual gemstone both in performance and the potential market value of the resulting design/ cut. With beauty being in the eye of the beholder, lapidary techniques must be applied to meet the eye of its new beholder (personal beauty) and the generations to come (timeless beauty).

Mass Market Vs. Small Business

Gemstones are cut for different markets based on that market’s perception of value. The two major attributes of the mass market for gemstones are color and weight. This is based on years of market development along with the original sizes and shapes of available rough gemstone crystals. The lapidaries that facet these gemstones are talented, but they are restricted to creating a standard and repeatable result to meet the size and color expectations of the industry. They do not have the luxury of forfeiting the gemstone’s color or weight for better light performance.

However, movement and play-of-light is the biggest component of a jewel’s performance. Many lapidaries prefer to create gemstones where light performance takes priority over weight and color. The artists and their clients see value in this. While weight and color are still top of mind, the beauty of the finished jewel is viewed from a different perspective than the mass market. It is not only the shape, design and size of the gemstone, but also how the light will play within it to create beauty for the new owner.

How to Cut Gemstones: The Science of Light

How to cut gemstones is the result of understanding and applying the disciplines of geology, gemology, geometry, chemistry and optics. Understanding the science of light and its movement within a faceted gemstone is important to get the brightest, most sparkling and most beautiful gemstone.

Material refractive indexes, dispersion and critical angles are major components to getting the best light performance from a gemstone Gemstone designer, Jim Perkins had a gemstone performance mission. He wanted to design gemstones that dazzled the beholder. He would create new and unique gemstone designs, but his forte was taking classic gemstone designs and maximizing their performance. He used to say that his designs were “10 percent inspiration and 90 percent perspiration,” meaning that he worked harder at the gemstone performance attributes of light return and scintillation than he did at making new geometric designs.

Client Satisfaction

On a personal note, I began using Jim Perkins’ gemstone designs and started to get immediate reactions from my jewelry design and setting clients. I remember the first couple of times I brought a set of Jim’s designs faceted in quartz, amethyst, citrine and rose quartz to show my jewelry clients. They were startled. I asked them what was wrong and they all said the same thing, “I didn’t know tourmaline came in this color.” I informed them it was a quartz gemstone and they all said the same thing, “You can’t make quartz do that!” But there it was in their hands, a beautiful piece of performance-based faceted quartz using Jim Perkins’ design, born from his perspiration and affinity for bouncing the light back to the viewer.

Light performance within a jewel has always been a major component of gemstone design. Over the centuries, we have been able to use science to better understand and apply the knowledge of light performance and crystal structure to our lapidary designs and techniques. In the past 50 years, lapidary has started to look at gemstone design and fabrication differently by using increased knowledge and newly developed tools. Cutters have found a growing market willing to pay for beauty that is both innovative and performance-based.

This story about how to cut gemstones appeared in Rock & Gem magazine. Click here to subscribe. Story by Mark Oros.

The post How to Cut Gemstones to Reflect Light first appeared on Rock & Gem Magazine.

ABOUT MOROCCAN SEAM AGATE

Moroccan seam agate’s colors are amazing, just like the fall in New England. The colors range from red, orange, pink, peach and green. They are sandwiched between a basalt host stone, and the outer layers are mostly a mix of hematite and goethite. This creates a beautiful border, that at times, has a plume or even a paisley appearance. The majority of the inside of this agate will have a common range of color from red to orange, with decorative banding or fortifications.

HOW TO BUY

When purchasing Moroccan seam agate, you can easily see the patterns showing on the edges. This gives you a good idea of what the slabs will look like inside.

Most of this agate will range from 1/4-inch to two inches thick. This isn’t very thick and it can be a challenge to create shapes from it. What Moroccan seam agate lacks in size, it makes up in color and patterns. Most of the time it’s best to slab this material from north to south. If pieces are a bit thicker and show signs of agate pockets, these can be sliced horizontally, and you can accommodate a different pattern.

CUTTING MOROCCAN SEAM AGATE

The slabbing process is fairly easy with this material. Most of the pieces are like trimming the edges off of a slice of bread. I do all my cuts on a 10-inch trim saw.

Once Moroccan seam agate slabs are cut, this is where the challenge starts. Creating cabs with long thin narrow pieces can be difficult, at least to create a variety of shapes. I tend to choose large oblong ovals or marquise shapes for the majority of my cabs, however, you can get creative and find various ways to cut them utilizing the patterns in each slab. Always take into account that the very edges of each slab are softer grainy basalt that won’t be very good to leave in your cab design, so mark out each preform accordingly.

CABBING THIS MATERIAL

Once your preforms are trimmed out, the cabbing process is pretty standard for most agates. There are just a few things to note upfront.

The outer basalt rind should be trimmed off until you reach solid material, then grind your edges down to your preform marks.

The hematite/goethite edges might be a slight bit softer than the agate center. Don’t worry. This material won’t undercut, however, you will still need to closely watch your edges as cracks may appear as you start grinding down your girdle edge. They usually don’t go all the way through, they tend to show up, but only about 1mm deep. If this happens, you may have to alter your pattern slightly and grind that portion down or draw the edge of your cab in ever so slightly. You may also just shrink down your girdle edge and see if that makes it go away.

From this point, shape and dome on the 80 grit steel wheel. Once your shape is obtained, you can start smoothing out the top on either a 140 soft resin wheel or 220 grit wheel. This should remove the majority of the scratches. Next, finish sanding on the 280 soft resin wheel and continue to dry the cab off checking for any remaining scratches. It’s important to get all of the scratches out on this wheel before moving on since the 600 grit will not be able to get them out.

From this point, the remaining routine will finish off your Moroccan seam agate cab leaving a beautiful high polish on the 14k grit wheel and your cab is all ready to set into jewelry.

This story about Moroccan seam agate appeared in Rock & Gem magazine. Click here to subscribe. Story by Russ Kaniuth.

The post Moroccan Seam Agate: What to Cut first appeared on Rock & Gem Magazine.

Our magazine writers have been reflecting on their most cherished rockhound gifts and what they hope to find under the tree. Whether it’s a practical tool, a book that has become a trusted companion or a beautiful specimen piece, these gifts reflect the essence of rockhounding – a shared appreciation for Earth’s treasures, minerals and jewelry.

We hope you’ll find inspiration and ideas for gifts for rock collectors and for celebrating the season with the fellow rockhounds in your life.

“Anyone who knows me knows how much I love Silverton, Colorado — its history, mines, people, scenery and of course, the train. They also know that a good book is always on my wish list. Over the years, I have purchased over 60 books from Silverton local, Scott Fetchenhier of Fetch’s Mercantile. Scott is a geologist, miner, snare drummer in the town band and the author of one of my favorite books, “Ghosts and Gold,” the history of the Old One Hundred Mine just outside of Silverton. These days, the Old One Hundred offers tours and is owned by Bill Jones, brother of Bob Jones, editor emeritus of Rock & Gem magazine. It would make a wonderful gift if your rockhound has these same interests. I also included a second favorite book — a coffee table book of black and white photographs of San Juan County, Colorado mines, mills and Ghost Towns which tickles my fancy of mines and photography by local, Colorado photographer Thomas Livingstone, “Historic Treasures of the San Juan Mountains”–also purchased from ‘Fetch.’” – Sue Eyre

“I usually don’t receive rockhound gifts from my family because I have too much stuff already. Although, a couple of years ago, I did receive a slab of Davis Creek obsidian from my grandson who accompanied me on a rockhounding trip to Northern California and Southern Oregon.” – Bob Rush

“My rockhounding partner in crime (and dirt), Charles, gave me a mother-of-pearl necklace years ago that I adore to this day. I love the origin story of this mineral otherwise known as nacre and, as a Cancer and water sign, I do believe these natural gems of the sea resonate for me in calm and healing ways. We’re hoping to visit Washington D.C. for the holidays, so if Charles will indulge me in a visit to the Smithsonian’s mineral and gem collection at the Museum of Natural History to say ‘hello’ to the Hope Diamond (especially after enjoying Steve Voynick’s October article on its purported curse), that’s all I could ask for (okay, and maybe a new pair of Uggs).” – LA Sokolowski

“My father, Floyd Painter, was given a small assortment of Carboniferous plant fossils collected at Cloyd’s Mountain in Pulaski County, Virginia, by an anthropology student at Old Dominion University as a trade for some Native American artifacts. The fossils included some fossil fern carbonized imprints on shale, a small (6-inch) piece of a Lepidodendron trunk, the leaves of Sigillaria, a giant lycopod, as well as one large (9-inch) Stigmaria fossil of gray sandstone. My father gave me this and a couple of the smaller pieces for Christmas of 1991 or 1992. They are my favorites because they were part of the very first real forests in the world, forests composed of strange-looking, huge versions of plants whose modern relatives are so small that they are often not even noticed in the woods and fields. There is nothing quite like them in the world today and if I show them to people, they will hopefully remember them for the amazing things they are and not just think of them as some old shell. This year, I’m asking for a gift card to an airline to put toward fare for a trip to observe and/ or collect more fossils and minerals.” – Deborah Painter

“I know it is sacrilege, but I really do not need any rocks, gemstones or crystals. In fact, I really need to sell one or two thousand pounds of stones, but giving these away for holiday gifts is not always a thoughtful or personal gift. So, this year, I am buying my rockhound friends the agate book bundle by Marco Campos Venuti. The two books in this bundle are Genesis and Classification of Agates and Jaspers: A New Theory and Banded Agates: A Genetic Approach. Being a self-confessed agate enthusiast, I find the two books fascinating in their exploration of the origin of these beautiful gemstones and the photos capture some of the most wondrous agate specimens in the world. After reading these books, or just looking at the pictures, I guarantee you will never look or think about agates the same way again.

“This holiday season, I am asking Santa for the Deluxe Hardness Pick Set from mineralab.com. Sure, asking for a specific gift rules out the element of surprise, but it is something I really need in my lapidary studio and it is a gift that won’t need to be returned. This is a replacement gift because I have almost worn out my current pick set. It is an essential tool for me to identify rocks and gems quickly. I already have a specific gravity testing setup, dichroscope, refractometer and other gem identification tools, but the Deluxe Hardness Pick Set is my first line for identifying rough rocks and gemstones. It is not to be used on finished gemstones and lapidary art. Although my old pick set is still working, a new one will ensure accurate testing and I can give my old one to a junior rockhound in need.” – Mark Oros

“My favorite gifts are books, everything from field-collecting guides to the full range of Earth science topics. They don’t wear out and never lose their value or use. I’m hoping to get the Maine edition of the great Roadside Geology series by Mountain Press to add to my home library this year.” – Steve Voynick

“My daughters bought me an Estwing paleontological hammer with a leather grip and had it engraved with my moniker PALEOJOE. That hammer has seen a great deal of use and made some wonderful discoveries. My next wish is for a Marine Corps K-Bar knife and sheath. Believe it or not, it works great for splitting sediment while looking for dinosaur bones.” – Joe Kchodl

“My favorite gift was a UV flashlight that enables me to check out new specimens. Before receiving this gift, I had a little dinky light that was practically useless unless it was completely dark. This light is powerful enough to use while I’m standing up with the room light on. I am pretty certain my friend got it from Amazon. It’s a uvBEAST Black Light UV flashlight. For the holidays, my friends and family know that any type of geode that I do not have is welcome. The quest for this may well be the premise for a new Mission Impossible flick!” – Richard Gross

“The gifts I enjoy most are the ones I give. The first gift is a 350-pound polished malachite from Africa. It was given to the Alfie Norville University of Arizona Gem and Mineral Museum in Tucson in memory of my first wife who was a U of A graduate. The next gift is set to go to the Pima County Gem and Mineral Museum. It is a large mass of schist with several emeralds embedded in the schist and the upper part is a series of carved busts.” – Bob Jones

“My favorite rockhound gift? Art Clay Silver. It provides hours of fun transforming sand dollars and other little marvels tossed up along our local beaches into pure silver jewelry that I, in turn, can give as gifts throughout the year. For this year, Santa, bring more Art Clay Silver! Not to be greedy, but Art Clay Gold would be good, too!” – Jim Brace-Thompson

“My favorite rockhound gift was my first pair of good steel-toed hiking boots that I received for Christmas in 1980 when I was a sophomore in college. I was about to leave for my first real field geology class that January, and it was great to have a pair of boots that did not fall apart in the wilderness. Many of my fellow students had cheap boots that literally came apart at the seams in the mountains, but my quality boots stayed intact. As I recall they were a pair of Timberlands.

“The rockhound gift that I am asking for this year is for as many family members as possible to join me on a rock-collecting trip to the mountains. Field trips are more enjoyable with lots of people, but I will settle for anyone who wants to come. Getting family motivated to come on field trips is often a challenge!” – Robert Beard

“My favorite in my gifts for rock collectors list is an amethyst bookend from my daughter. She bought a pair of them and kept one for herself and I have the other. This is special because she is moving away from home for her first job. It has such a sentiment for me as my first child leaves the nest.

I do have some picks for gifts for rock collectors as the editor. These are great products for rockhounds to consider as they are making purchases this year. The first is an Easy Saw Rotating Clamp (www.easyrotatingclamp. com) for jewelry makers. According to their website, “It features a 360-degree rotating clamp that can securely hold a variety of materials, including sheet metal, carving wax, and coins.” If you do purchase this and make some jewelry with it, please share photos of your creations. I’d love to see them.

My second pick is the Tumble-Vibe 10 (No Drain 115V) Professional Rock Polishing Kit from Raytech (www.raytech-ind.com). This tumbler takes your game to the next level and is designed specifically for rockhounds. It has everything you need to immediately plug and play (minus the rocks).

Last but not least is a faceting machine from Ultra Tec. If you’ve been thinking about learning to facet gems, Ultra Tec offers top-quality machines and superb customer service to help in your journey. I like Ultra Tec so much that I’m often tempted to learn how to facet myself.” – Pam Freeman

This story about gifts for rock collectors appeared in Rock & Gem magazine. Click here to subscribe. Story by Pam Freeman.

The post Holiday Gifts for Rock Collectors first appeared on Rock & Gem Magazine.

Opal is a well-known example of a mineral whose color is caused by a physical phenomenon called “diffraction.” Other phenomena include iridescence, a rainbow effect seen in iris quartz and pearls; chatoyancy, which we see in cat’s-eye stones and some malachite; asterism, which is displayed in star stones; aventurescence, as seen in aventurine quartz and sunstones; adularescence, seen in moonstone; and play of color, or the alexandrite effect, seen in the alexandrite variety of chrysoberyl and some garnets. In every one of these groups, the cause of the color is related to some internal physical structure and not a metallic impurity or element in the mineral’s structure.

Opal Color

For centuries, people tried to explain the play of color seen in many opals. Finally, in the 1960s, we developed equipment that could actually see the internal structure of opal. It revealed a very orderly arrangement of submicroscopic spherules of silica. These spherules and the spaces between them acted as a diffraction grating, spreading light into its various colors. The sizes of these spherules and the angle the light struck them, coupled with the viewer’s angle, determined which color wavelengths were canceled and which ones were reflected. Diffraction of light results in opal’s play of color.

Labradorite Color

A more common mineral that gets its play of color from diffraction is the feldspar mineral labradorite. This mineral can develop in huge formations, resulting in outcrops that give off flashes of color.

Labradorite crystallizes in thin wafers in parallel layers that repeat to form a diffraction grating. This has the effect of separating light into its colors, giving labradorite a play of color that depends, in part, on the angle of the source of light. The thickness of each crystal and each cluster of crystals in their parallel layers also affect which color is seen. Labradorite can flash bronze, blue, green, and in some cases, red or violet in an overall groundmass of gray to blue. It is thought the gray color of the groundmass is due to the scattering of light by the internal structure.

Play of Color

Another attractive feldspar mineral is adularia. Like labradorite, it develops as thin crystals that line up in parallel arrangement and act as a diffraction grating. But adularia does not show a play of color. The twinned arrangement of the crystals simply scatters light. While it can also be shades of gray, pink, peach, green and brown, it is best known for a bluish-white color that is reminiscent of the moon.

Properly cut adularia gives off a cloudy sheen that seems to float throughout the polished stone. We give this lovely form of adularia the name “moonstone.”

Why does adularia have little color, while labradorite is a riot of color? Minerals color variations are because of minor variations in the refractive index of the labradorite crystals involved. In adularia, the refractive indices of the crystals are virtually the same.

Iridescence

Iridescence is described as a play of changing colors on a surface of a mineral. A prime example is the look of oil spread over the surface of water. The oil particles have a different refractive index than the water, and this physical difference results in a play of color.

The most common example of this phenomenon is called “peacock ore”, which is actually the mineral bornite (copper sulfide). A freshly broken surface of bornite quickly oxidizes, forming a thin oxide mineral layer whose refractive index differs from bornite’s and creates a play of color. More subdued examples of this iridescence are seen on some crystal surfaces of pyrite, cuprite, chalcopyrite and hematite.

Pearl Iridescence

Iridescence is what gives pearls their soft, moonlike luster, called “orient.” Pearls are made up of layer upon layer of microscopic crystals of hexagonal aragonite. The refractive indexes of these layers are the same. Colored and black pearls result from inclusions that get into the pearl’s structure.

Mother of Pearl’s lovely shimmer, or glow, comes from the interior lining of shells, which is made up of two different substances: the calcium carbonate mineral aragonite, which forms microscopic hexagonal crystals, and conchiolin, a fibrous protein that forms in layers in parallel arrangement. The parallel fibers of the conchiolin are the key to creating the iridescence we see in mother of pearl, also called “nacre.”

Chatoyancy

When the fibers of a mineral develop in a parallel arrangement, they impart a silky shimmer or glow of light, called chatoyancy, that can be very appealing. You can expect to see this shimmer in a range of minerals. Asbestos is a very common example. When the asbestos is invaded by silica, it can form what we normally call tiger’s-eye, which is a very useful chatoyant gemstone with a silky luster. The invading silica negates the hazard we normally associate with asbestos.

Iridescence Within Stain Spar

One variety of gypsum, called stain spar, also shows iridescence, or glimmer of light. The mineral looks like silk cloth, whose fibers are also arranged in a tightly woven, parallel structure. Another example of iridescence is seen in some malachite. This copper carbonate usually crystallizes in tightly packed needles, which grow in slightly diverging radiating masses. When freshly broken, these near-parallel fibers give off a shimmering green color.

Asterism is seen in minerals like diopside, gem corundum, some moonstones, and several others. In these species, included fibrous crystals of the mineral rutile, in an intersecting arrangement, reflect light in a six-rayed star pattern. This physical phenomenon is what creates rare star sapphires and rubies, which are very valuable varieties.

Cat’s-eye gems exhibit chatoyancy, as well as a single, bright, linear reflection from tightly packed parallel fibers of a second mineral. Lapidaries give these gemstones a slight to strong dome and orient them so that the included mineral, often rutile or tourmaline, runs straight across the curved surface to form a single bright line, much like the vertical iris in a cat’s eye. It is important to know that these included needle crystals are all oriented along just one of the several growth axes of the hexagonal corundum stone.

Hexagonal Minerals

Hexagonal minerals like ruby and sapphire develop along four axes: one vertical “C” axis, from which three axes develop at right angles to the “C” axis, 60º from each other. For a star gem to form, the included mineral orients along the two arms of each horizontal axis to create a six-rayed star.

Chatoyancy is also seen in the cubic mineral gem garnet. The difference is that garnets form in the cubic system so the “star” forms from needle crystals that have oriented along the two horizontal axes that make up the cube form. Only two axes extend away from the single vertical axis, so the four arms of these axes with their parallel, included needles can orient to form a four-rayed star.

Understanding Aventurescence

Aventurescence is another physical phenomenon that involves inclusions. In this case, the inclusions are usually large enough to be visible and are scattered throughout the crystal mass, rather than oriented in a particular alignment. These scattered inclusions act as reflectors that scatter the light entering the host mineral.

An intriguing example of this is the manmade material called “goldstone”, which is glass with copper inclusions that give the glass a bright reddish-gold color.

Aventurescence is named for a quartz variety called aventurine, which is a lovely green color thanks to included chrome mica. These tiny, green flakes, or spangles, are scattered throughout the quartz, giving it a diffused green color of varying intensity that is very attractive.

The most attractive gem that falls into this category is the feldspar variety sunstone. This very lovely gem is found in several places in Oregon and shows a fine orange to red color due to included copper diffused throughout the gem. In some examples, the copper orients within the feldspar so that wisps and feathers of color are prominent in the gem. Sunstone claims in Oregon are occasionally opened to collectors for a fee.

Alexandrite Effect

Finally, the alexandrite effect is seen in very few minerals whose color is based on the type of light source. The chrysoberyl variety alexandrite is the obvious example.

Alexandrite has a light absorption band that, in sunlight, can split light into two different transmission areas. Under sunlight and fluorescent light, some of the blue wavelengths are absorbed, so green becomes dominant. When seen under in incandescent light, alexandrite is red.

As you collect colorful minerals, be aware that not all of them owe their color to a trace element inclusion. This is another area of interest you can pursue as you enjoy our wonderful hobby.

This story about what gives minerals color appeared in Rock & Gem magazine. Click here to subscribe. Story by Bob Jones.

The post What Gives Minerals Color? first appeared on Rock & Gem Magazine.

This is the first in a three-part series also covering types of gemstones with the letters J to R and types of gemstones with the letters S to Z.

What is a Gemstone? The definition of a gemstone isn’t quite as precise as the faceted beauties it describes. In general, when minerals, and sometimes organic materials such as amber, are cut and polished to create jewelry, we call them gemstones. There are nuances and outliers because some types of gemstones are too delicate to be worn, but most people in the gem world accept this general concept. To further clarify, types of gemstones are divided into “precious and semi-precious” stones with only diamonds, emeralds, sapphires and rubies encompassing the precious category. Everything else falls into the semi-precious zone, although this doesn’t necessarily imply inherent modern value or desirable characteristics. Regardless of the classification, there’s no question that when we can bring out the inherent beauty within these stones, it is something to be truly prized.

Agate

Agate is a silica-based mineral and is a popular semiprecious stone because of its attractive coloration and banding. Reportedly discovered by Greek philosopher Theophrastus roughly 2500 years ago, early people throughout the Middle East, Russia, and Greece used agates to create ornaments. According to research by the Bureau of American Ethnology, Indigenous People utilized them in much the same way.

Agate is a chalcedony, which is a type of cryptocrystalline quartz. Like many stones in this category, it’s created when groundwater seeps into the igneous rock where silica deposits form concentric layers within the rock cavities and crevices to create the telltale banded patterns.

The wide variety of colors, ranging from brown, black, white, red, gray, pink and yellow, are because of impurities in the groundwater. With a seven on the Mohs rating, agates are on the upper end of the hardness scale. This makes this translucent stone a favorite for rock tumbling. It’s often used for jewelry as well.

Bloodstone

An opaque, dark green type of gemstone, bloodstone features distinctive orange to scarlet red splatters that look like blood at first glance. This is the telltale signature of this traditional birthstone for March. The more modern birthstone choice is aquamarine.

Bloodstone is also called heliotrope, a name derived from the Greek helio meaning sun and tropos meaning toward the sun. If you garden, you’re familiar with heliotrope plants that turn toward the sun as they grow. This name indicates how the stone reflects the light. Along with legends of healing powers, bloodstone is also known as a protective stone. People will often wear or carry bloodstones to keep threats at bay.

The minerals chlorite and amphibole are responsible for the deep green coloration while iron oxide inclusions create the blood-red speckling.

Carnelian

Carnelian is one of the least expensive chalcedonies, the translucent yellow-orange to rich amber or even reddish-brown gems darken when heat treated. This includes the heat of the sun, so it’s best to keep your stone out of the sun to keep the color true. Iron is responsible for the red coloration and it’s what oxidizes and deepens when exposed to heat.

Carnelian is sometimes confused with jasper, although jasper is a type of gemstone that is typically a deep red and is opaque, rather than translucent. Plus, jasper often exhibits banding patterns on its surface appearance.

Carnelian is found throughout the world with some of the highest quality stones found in Scotland, Brazil and Washington State.

Even though it’s relatively inexpensive, many so-called carnelians are dyed and heat-treated agates. To determine if a carnelian is real, hold it up to the light. If it’s a natural carnelian, it looks cloudy. If it’s a heat-treated agate, it will most likely show striping.

Dumortierite

Although colors range from brown, green, and the rarer violet and pink, the eye-catching denim blue of this type of gemstone is probably the most popular with gemstone enthusiasts.

An aluminum boro-silicate mineral, dumortierite occurs in regions of high metamorphic activity that are also rich in aluminum and boron. Manganese, iron, and sometimes zinc inclusions, are responsible for the blue coloration.

Dumortierite was first described in 1881 after being found in the French Alps. It was named for the French paleontologist, Eugene Dumortier.

Dumortierite has a glassy (vitreous) luster. Its fibrous nature creates fine, almost hair-like radial crystals within the structure. The blue variation is sometimes mistaken for lapis lazuli, but dumortierite is typically a deeper blue or violet, plus lapis lazuli sports white or gold metallic flecks because of the pyrite within it.

Dumortierite quartz is quartz with inclusions of dumortierite.

Emerald

The birthstone for May, emeralds are a type of gemstone that earns their place as an adjective to describe a particularly intense green. The name is derived from the Greek word smaragdos, meaning green stone.

Created in metamorphic rocks when hot magma flowed over and through the crevices of limestone and shale, emeralds are a beryllium aluminum silicate. Although emeralds are a type of beryl, not all beryls are emeralds. While green beryl is still green, it’s distinctly lighter.

Chromium oxide is responsible for the emerald’s deep green. Other gems, such as peridot and tsavorite garnets, are also found in green hues but not with the same vibrancy. Registering 7-8.5 on the Mohs hardness scale and forming in hexagonal crystals, emeralds are long favorites for precious jewelry, but fakes abound. To determine authenticity, inspect the stone with a 10X loop. Flaws and inclusions, particularly a small crystal within the stone, indicate a natural emerald. Air bubbles or even a “too perfect” stone are tell-tale signs that it is not real.

Fluorite

Made of calcium fluoride, pure fluorite is colorless, yet samples are commonly found in shades of purple, golden-yellow, green, blue, pink and brown. These types of gemstones are translucent to nearly transparent with attractive banding. The term “fluorescence” became part of the terminology when physicist Sir George Gabriel Stokes was working with fluorite in 1852. Although fluorescence doesn’t consistently occur, fluorite is known to glow when there is the presence of uranium, yttrium and other rare earth elements. It often emits blue, although yellow, green, white and red shades are possible.

Also called fluorspar, it’s been produced in Illinois since the 1800s and is the state mineral. Often forming in cubic crystals, it is popular for jewelry but has a wide number of commercial applications ranging from an ingredient in ceramics to a flux used in refining metals.

Garnet

Many people picture garnets as red stones, but these types of gemstones are also found in shades of orange, pinkish-orange, green, reddish-purple, colorless and even blue and green, albeit these last two are rarer.

Garnets are formed when aluminum-laden sedimentary rock is metamorphosed. Garnets are one of the most widespread types of gemstones throughout the world. While the bulk of garnets is mined for industrial applications, it’s one of the oldest known gemstones and has been used for ornamental purposes for 5000 years. Historical evidence shows stones within the necklaces of pharaohs. Garnet signet rings were used by Roman leaders to seal documents.

Sometimes mistaken for a ruby, garnets are usually a darker red with brownish tones. When it’s held up to the light, yellow bands are often visible in a garnet while a ruby will be clear.

Hematite

Consisting of 70 percent iron, hematite is one of the primary ores of iron. Fortunately, it is one of the most abundant minerals on Earth. According to NASA, it’s also the most abundant mineral on Mars. The iron-rich environment is why Mars is dubbed the “red planet.”

Named as far back as 300-325 BCE, hematite is derived from the Greek haima, meaning blood. These types of gemstones are found in colors ranging from rust-red, brown, steel-gray to black, it always leaves a red streak when scratched on a scratchpad.

The distinct reddish hue has been used in artwork from the earliest cave paintings. It was a key pigment for Renaissance artists creating paintings with canvas and oil in the Middle Ages. Besides its importance as an ore for iron and in art, it effectively stops radiation making it useful in shielding applications. Plus, it creates a beautiful tumbled stone for those who love to collect them.

Iolite

This beautiful violet-blue stone was the secret to the Vikings’ success in crossing the ocean as they looked through a thin iolite specimen to determine the position of the sun on cloudy days. The key to this unique quality is called pleochroism where different colors are visible at different angles. For example, a piece of iolite may have the classic violet-blue hue on one side, but when it’s turned over, it appears yellow or clear.

A silicate of aluminum, iron and magnesium, iolite (also known as the mineral cordierite) is created in metamorphic and igneous rock formations. Derived from the Greek word ios meaning violet, some iolite is blue enough to look like a sapphire. Some speculate this quality is because of the presence of titanium, although iolites are easily distinguishable because of pleochroism.

This story about types of gemstones appeared in Rock & Gem magazine. Click here to subscribe. Story by Amy Grisak.

The post Types of Gemstones By Letter (A-I) first appeared on Rock & Gem Magazine.

Starting a Rock Store

Isobel Medley was an only child and was raised in the early 1920s on a prairie farm in Carberry, Manitoba. She attended a one-room school with one teacher for first through 12th-grade students. Isobel developed a strong interest in rocks and geology in those formative years. She eventually moved to Vancouver, British Columbia. In 1945 she married Al, for whom she waited eight years for his return from the War. She became the mother of three children while studying geology. Her love of rocks ultimately inspired her to open a rock store.

The Fraser Rock Shop opened in 1960 and it became the place her daughter Velma spent most of her childhood every day after school. Velma holds many fond memories of her experiences there. For instance, the original shop was located next to a Chinese market – one that Velma frequented when the fresh produce was being delivered. She remembers the shop had an apartment upstairs and she often played with children who lived there.

Quickly though, the shop grew and needed more space. Isobel had visions of a larger shop and space to teach classes. Velma recalls that this move, also on Fraser Street, brought the shop closer to her middle and high school. Growing up in a rock shop, Velma developed skills that helped her throughout her life – listening, providing for each customer, public speaking, asking questions and developing relationships that lead to lasting clients. In those years, Velma didn’t realize just what a skilled lapidary her mother was.

Isobel was a lifelong learner and pursued lapidary skills that reflected her expertise and experience, and Velma learned those same skills.

A Family Affair

The Fraser Rock Shop may have been Isobel’s brainchild, but it was really a family affair. Velma recalls her father Al being an active part of shop operations. He was a career business agent and traveled during the week, but on weekends he was involved in cutting larger rocks — Brazilian agates, jades and petrified woods to name a few. Eventually, their mutual interest led Al to purchase a jade mine with a partner. Helicopters were needed to fly to the Birkenhead Jade Mine in the interior of British Columbia where huge, on-site saws were used by her father to cut pieces of jade which were later sold in the rock store.

Velma recalls that family vacations included spending time rock hunting. “It didn’t matter what direction we were traveling; we were always looking for rocks,” Velma explained. She still has a jar of opals she collected in Mexico on a family adventure. Trips also provided insights into how stonework was done in other parts of the world. For example, Velma remembers antiquated tools in use in Mexico and a stunning European trip where they observed rocks being cut by lapidary artists lying on their stomachs.

Rock Store Adventures

Growing up in the rock shop seemed natural to Velma. She didn’t realize how uniquely special it was until high school. Velma had many wonderful experiences working alongside her mom. For instance, she recalls her mom announcing her participation in a local children’s television program called “Show and Tell.” Her mom thought it would be a great experience for her and suggested she speak about thunder eggs.

Thundereggs are found in Oregon and are formed in rhyolite lava. Customers to the shop found them to be interesting – and would choose one to cut with a diamond blade saw to reveal their internal patterns and colors. “I was feeling mortified, scared and nervous,” Velma said. “Mom stayed focused on the positives and I being obedient and not wanting to let her down, agreed to participate.” While Velma doesn’t remember the filming beyond the gentleman who took her through it, the experience was an opportunity to learn and grow.

Another time Velma recalled waiting on a young, handsome man with curly blond hair. He wanted to have a special pendant made for his fiancé at the time. Her mother cut and polished the stone, setting it to his preselected settings. Later they learned that this young man was the Canadian musician Terry Jacks, famous for the song Seasons in the Sun.

Developing Clients

Slowly, Velma developed clients of her own. She worked for a visually impaired gentleman who paid her to polish the stones he would give as gifts. Velma’s mother tasked her with teaching a legally blind girl to shape cabochons on the grinder. This was a good challenge because it’s easy for a sighted person to grind away a layer or two of skin!

“There was a lot of activity in the rock shop, so it was fun being there,” Velma said. Not only were there classes for adults and youth, but often people came in and rented equipment by the hour. People renting equipment for .35 cents an hour always had her mom as a resource while polishing and cutting stones. The shop was a hub for rock club events, students of all ages and anyone interested in learning about rocks.

Lifetime Achievements

“I do admire the sense of achievement my parents shared throughout their lives,” Velma declared. “The joy of work for us, I think, could be attributed to all the wonderful people we met, helped, taught and encouraged.”

Velma went on to say that over the years, they had belonged to a couple of different rock clubs building life-long friendships that spanned fun annual gatherings, food, games, music and memories which of course included attending rock shows!

“Rockhounds come in all ages,” she added. “Even from prairie farms.”

Rocks for Sale

While Velma was living in Alberta, her parents sold the rock store in the mid-1980s, (or so she thought) only to fully realize after their deaths that they had retained their extensive collection of finished jewelry, cut and uncut stones. Recently, Velma has been working to sell the entire collection.

This story about growing up in a rock store appeared in Rock & Gem magazine. Click here to subscribe. Story by Deb Brandt.

The post Growing Up in a Rock Store first appeared on Rock & Gem Magazine.

After 30 years of procrastination, I purchased a brand-new rock saw and grinder/polisher. Wow, did I have fun! For that first few months of cutting and grinding, I was in seventh heaven. All those lovely rocks I had lusted after for so long were finally put under my polishing wheel: lapis, agate, jasper, tiger’s eye, malachite, turquoise, chrysocolla and quartz.

But I soon began to experience a nasty and completely unexpected cavalcade of health problems: coughing, hoarseness, difficulty clearing my throat, breathlessness, and a dull ache in the pit of my lungs. Of course, I had always worn safety glasses with side protection, as recommended in every manual, but a mask seemed a cumbersome hindrance. As the situation worsened, I tried several dust masks, but there was little improvement. It was time to do a little research, so I hit the books and started talking to fellow rockhounds. It was a revelation. Rock dust from lapidary work turns out to be more than just a nuisance; it can be deadly.

Dangerous Dust

A single heavy dose can cause crippling lifelong problems. It attacks the lungs in a variety of ways: First, by coating the inner lining and blocking the transmission of oxygen into the bloodstream. Second, tiny sharp fragments slice and cut into the alveoli, which coat the inner lining of the lungs, causing irritation and inflammation. Fresh dust seems to be more harmful because the sharp edges have not had a chance to be softened by moisture. Some forms of rock dust are quite poisonous in and of themselves. Whether it is inhaled, ingested, or contacted by exposed skin, the effect can be injurious to your health.

Copper Oxide Minerals

Among the worst offenders are minerals containing copper (II) oxide (CuO), the higher oxide of copper, which can cause damage to the endocrine and central nervous systems. These minerals include some of our most colorful and treasured semiprecious stones: turquoise (9.8% copper oxide), chrysocolla (45%), and malachite and azurite (70%). These percentages are only close approximations; each rock has its own signature of impurities.

It is worth remembering that other closely related copper compounds are highly bioactive and have been used in pesticides, fungicides, and wood preservatives for decades. This is dangerous material. These high-copper rocks should not be licked to bring out the color, and oil mixed with the dust should be carefully cleaned off exposed skin.

Several lapidaries who smoke have described their own novel test for overexposure: Apparently, copper-impregnated dust combines with nicotine and tobacco tar in saliva to form a sickeningly sweet compound similar to saccharin. When their mouths start to taste like a candy factory, these rockhounds know it’s time to quit. Another sign is influenza-type symptoms. Symptoms of CuO dust poisoning mimic the flu, causing headaches, coughing, sweating, sore throat, nausea and fever. Skin, eye, and respiratory tract irritation are also common, along with a distinct “metallic” taste. A common name for these health effects is “metal fume fever.”

Silicate Minerals

Almost all the rocks most favored by cutters and polishers contain compounds that can be dangerous when inhaled. Silicates are the most common family of minerals on Earth, and silicosis has long been one of the chief hazards facing stonemasons.

The ancient Greeks and Romans were the first to observe its ravages and correctly associated the problem with mining and rockwork. Similar to the “black lung disease” of coal miners, it came to be known in later years as “grinder’s consumption.” The simple steps taken to prevent it were a major achievement in the modern field of occupational health. Ironically, although silicosis is well understood today, thousands still die from its effects every year, mainly from mining and sandblasting in the third world.

The symptoms of inhaling crystalline silica (SiO) dust include shortness of breath, cough, fever, emphysema, pulmonary fibrosis, lung scarring, and increased susceptibility to tuberculosis and cancer. Silicosis often takes many years to develop from repeated exposure to low doses of dust, but once established it is irreversible.

Widespread Silicates

The silicates include a bewildering variety of precious and semiprecious stones. In fact, it’s hard to imagine the world without them, as they can be found in every class of rock and occupy a niche in every conceivable geological environment on the planet.

The family includes quartz, chalcedony, jasper, agate, aventurine, bloodstone, carnelian, chrysoprase, amethyst, opal, onyx, beryl, petrified wood, obsidian, flint, chert, soapstone, sandstone, glass and tiger’s eye. In almost all of these, the content of silicon dioxide approaches or exceeds 50%.

It should be mentioned that African tiger’s eye also exposes the lapidary to another potent danger: asbestos. The vibrant optical effect of its chatoyancy is caused by parallel-oriented, finely fibrous amphibole asbestos. Serpentine has a high chrysotile asbestos content, but this is not considered quite as dangerous as the tiger’s eye. Some soapstone varieties also contain asbestos and should be cut or carved with caution.

Fossil Dangers

Radioactivity from fossils is a hazard that isn’t often top of mind. In a recent study of 300 randomly selected fossils from the Hagerman Fossil Beds of Idaho conducted by C. Neal Farmer, Ronald L. Kathren, and Craig Christensen, a handheld Geiger-Müller survey instrument detected discernible levels of radiation one to two orders of magnitude above the ambient level of background radiation in three-quarters of the specimens (“Radioactivity in Fossils at the Hagerman Fossil Beds National Monument”, Journal of Environmental Radioactivity, Vol. 99, Issue #8, August 2008, pp. 1355-1359). That is a huge difference.

In some areas, like the Hagerman Fossil Beds National Monument (Idaho) and the Morrison Formation at Dinosaur National Park (Colorado/Utah), fossils have even been hunted using Geiger counters.

According to the study, radioactive fossils seem to occur most commonly between 900 and 1,000 meters above sea level in ancient sandy riverbeds, while clay-rich deposits and those at other altitudes do not seem to show these high levels. Apparently, naturally occurring uranium produces radium, which decays into radon, an inert gas. Ancient groundwater transported these radioactive elements into sandy fossil-bearing areas, where they precipitated out of solution during the fossilization process. Even small fossils like shark teeth and trilobites can have significant readings.

The National Park Service is so concerned that it put out a “Conserve O Gram” with detailed instructions for handling and displaying specimens. While it is probably safe to collect most fossils, at the very least, you should wash up and change your clothes after leaving the field. And always wear a respirator when you cut or polish the pieces—radioactive dust is highly carcinogenic!

Tips for Safe Handling

But enough of the doom and gloom. A few simple precautions can almost completely eliminate the threat of injury from most rock dusts. Here is a list of suggestions that will make your workshop a lot safer and allow you to enjoy lapidary work in good health.

1. Wear a Mask

Always wear a National Institute for Occupational Safety and Health (NIOSH) approved respirator with replaceable cartridges and dust filters. Some cartridges today combine a prefilter with the cartridge, which makes things simpler.

Respirators provide a wide variety of protection against dusts, solvents, fumes and mists. They are designated N, R and P, depending on the cartridge’s ability to filter out oil; N stands for “no protection”, R for “resistant to oil”, and P for “oil-proof”. The number that follows the initial tells you what percentage of the particulates is filtered out by the cloth prefilter. For example, an N-95 respirator will not keep out oil spray but will screen out 95% of airborne dust particles.

Avoid cheap dust masks; they don’t fit tightly enough and they filter poorly. If you can, try on several different respirators at the store to get the best fit. Shave your beard, if you have one, to get an airtight seal. Store the mask in a closed container or plastic bag when it’s not in use, and occasionally wash it with warm soap and water, both inside and out.
Try this simple negative pressure test on your respirator: Block up the air inlets, breathe in, and hold your breath for 20 seconds. If the mask is still held airtight against your face, it fits. Cartridges should be changed after about eight hours of use.

2. Work Outside and/or Ventilate

An open window or air conditioner does not provide adequate ventilation for the lapidary workplace. The simplest solution is to work outside. This keeps most contaminants out of your workshop and costs nothing, but it is not always possible.

If inside is your preference, consider setting up a local exhaust ventilation system. This would include a dust hood to collect contaminants, ducts to carry them outside, and a suction fan to power the system. Adjustable blast gates would allow a dust hood to be placed next to each appliance. Ducts should be circular, with as few bends as possible, and should exit the shop. If you have close neighbors or are processing a lot of rock, provide a dust collector to remove contaminants from the vented air.

Setting up such an elaborate system can be expensive and time-consuming for the part-time hobbyist. Some woodworking tool suppliers have come up with an ingenious alternative. They have adapted a wet/dry-type vacuum cleaner with a High-Efficiency Particulate Absorbing or Arresting (HEPA) filter to collect shop dust using a little extra pipe and some suction nozzles. There is no reason this system should not work for rock dust, as well. The vacuum should be placed outside the house because the dust-laden air sucked into the intake will be blown out the vacuum’s exhaust port. Even HEPA filters fail or become clogged, and some dust will always slip through. It’s far better for it to be blasted outside than into the shop or another enclosed area. Kits, diagrams, pipe and suction nozzles are available on the internet. Search for “dust collection” and “dust collection network”.

3. Lubricate

Always use water or oil as a lubricant when cutting, drilling, polishing or faceting, but be aware there are problems with both fluids. When water evaporates, it stops holding the dust down, allowing it to become airborne. A fine oil mist laden with toxic dust can be kept out your lungs with a good respirator, but it will settle on skin surfaces and stick like glue. Also, most lapidary oils are highly irritating or downright poisonous to breathe. Some, like old-fashioned kerosene, are dangerously flammable, as well. Everyone has their favorite method, but I work outside using mineral oil and a P (oil-proof) respirator cartridge with a built-in 100% particulate filter.

4. Cover Up

Always wear a head covering and apron and/or coveralls when grinding, and change clothes after you have finished. Rock dust loves to stick to clothing and hair, and you will carry it around the house and breathe it all day long (as will your family) if you don’t change. Take a shower after your lapidary work, shampoo your hair and use lots of soap. Launder coveralls and work clothes frequently. Disposable clothing, coveralls, and an apron might also be an option.

5. Don’t Sweep

Never dry sweep the workshop. Most of the dust will just become airborne and migrate elsewhere. Use a vacuum cleaner with a HEPA filter instead. If you really want to get down and dirty, use a wet mop on the floor and a wet rag with a water bucket on other surfaces.

Not all of these suggestions need to be slavishly followed. If you grind infrequently, you can probably forget some of them, but if you are an addict like me, you might want to implement most. Individuals vary greatly in their tolerance to rock dust. Some will go through life with nary a problem, but others can be extremely sensitive. Low doses on a daily basis will slowly accumulate, and that dust isn’t going anywhere once you breathe it in. Smoking and living with a woodstove or in an area with poor air quality will make you that much more vulnerable to problems. Listen to your body. If your lungs start to complain, take more precautions; you only have one set to last a lifetime.

FURTHER READING: Health Hazards Manual for Artists, 6th Ed., by Michael McCann Ph.D. and Angela Babin (Lyons & Burford Publishers, 2008)

This story about how to handle lapidary minerals safely previously appeared in Rock & Gem magazine. Click here to subscribe. Story and photos by Douglas Hamilton.

The post 5 Tips to Handle Lapidary Minerals Safely first appeared on Rock & Gem Magazine.

In Montana, gold and silver drew those looking for wealth to these remote realms. In the 1860s, prospectors found a smattering of gold in the waterways, although silver quickly drew more attention. By the following decade, it was silver that launched the mining empire of future moguls, William A. Clark and Marcus Daly, who segued into copper as the silver market cooled.

With technological advancements in mining and smelting, copper gained momentum beginning in the early 1880s. A pivotal moment was when Daly visited a newly blasted shaft in the Anaconda Mine, and after examining the black rocks containing the copper ore chalcocite, he reportedly proclaimed that Butte would be “the richest hill on earth.”

His pronouncement became a reality. According to the Mining History Association, in 1896 Butte produced 26 percent of the world’s copper supply and 51 percent of the United States’ needs as one smelter alone produced two million pounds of copper every month.

An International Metropolis

Butte is currently home to around 35,000 people, however, Aubrey Jaap, the director of the Butte-Silver Bow Public Archives, says that “(Butte) really peaked before and during WWI.”

By 1917, the population reached 100,000 with approximately 450 mines in operation. Nearly unlimited work opportunities drew immigrants from throughout the world with the note-worthy saying, “Don’t stop in America, go straight to Butte!” There were so many ethnicities that no-smoking signs within the mines were typically displayed in 16 different languages.

Butte was ethnically diverse and bustling with energy. It was a cosmopolitan city when much of Montana was not much more than cow towns. With the abundance of drive and expertise, the architecture of the growing city reflected the ambitions of its residents. International cultures lead to world-class restaurants and active civic organizations. At its height, Butte was a city that never slept.

Hardscrabble Life

This prosperity came with a price as wealth was built on the backs of the miners and their families.

“It wasn’t an easy place to live,” said Jaap. “There were no trees because they needed timber for the mines and to feed the furnaces.” With the smoke and pollution from the continually churning smokestacks, it was the image of industrialization.

“There was noise in town all of the time,” said Jaap who noted residents were accustomed to the constant hum of commerce. “What was scary was when it stopped,” she said because this typically meant a tragedy in the mines.

Deepening Mine Shafts

Initially, mining began with a pick and shovel, with explosives expediting the process while evolving into utilizing a windlass for shallow depths, and then a whim where a horse walked around a pivot to hoist up men and materials. As the mining shafts deepened, headframes, many that still dot the landscape, stood up to 200 feet tall to transport ore and workers sometimes over 5000 feet deep.

It was another world working underground. Extreme conditions took their toll. Jaap noted in the early days the men would emerge from the hot conditions of the mine soaking wet from sweat, water used in dust abatement and natural water within the mine itself. During the winter, temperatures rarely climbed above freezing and often hovered around -40°F. When the men came out of the mine in wet clothing into the bitter cold, they often succumbed to sickness, including pneumonia. This was resolved in later years by a dry room where they could change into dry clothing at the end of their shift.

Men had to work in pairs as a rudimentary safety system. They typically worked 12-hour shifts. Before electricity, candles and oil lamps were used for light.

Initially, the men shoveled all of the material in the carts, and while a man could push a single cart once filled, a horse could pull up to five. Horses and mules spent years in the mines before their own poor health, or death, was their ticket to the upper world once again. This practice continued until pneumatic locomotives, and eventually, electricity supplied the power. The last horse was brought up from the Emma Mine in 1937.

A Dangerous Profession

There were lots of ways for injury or death in this profession. Besides the taxing working conditions, breathing stale air and dust caused a condition called silicosis or “miners consumption.” Constant exposure to heavy metals contributed to cancer and inflammatory diseases and accidents were common.

Working with explosives was also dangerous. After drilling holes, miners placed a stick of dynamite in each using a piece of wood to carefully push it into place. This is where the common phrase, “Tap ‘er light,” came into being. Fuses were grouped 12 to 15 in a bundle. Workers had roughly eight to 14 minutes to get away from the blast zone once it was lit.

Even equipment that was supposed to make life easier could be deadly. The mucking machine, which was brought on board to save the men from shoveling, could decapitate miners.

It’s estimated that over 2,000 men died in the mines.

North Butte Mining Disaster

On June 8, 1917, during the height of production with well over 14,000 men working around the clock to supply the copper needed for World War I, 410 men descended into the Speculator Mine for the night shift. A cable falling to the 2400-ft. level created a cascade of events that left 168 men dead.

Just before midnight, four men lowered into the shaft to retrieve the five-inch diameter electrical cable that was being installed to create a fire alarm system. What they didn’t realize was when the electrical cable fell it tore the protective lead exterior of another nearby cable, exposing the paraffin-coated paper used for insulation. When one of the worker’s carbide lamps accidentally touched the cable, it ignited immediately. The mine shaft became a “mighty geyser,” and the sound of the disaster woke residents. Flames and toxic smoke turned the levels into a smoke-filled maze, killing or trapping nearly half of the men.

Personal Stories

Quick thinking during the disaster saved lives. For example, Mannus Duggan, a 25-year-old nipper (a worker who sharpened and made sure the men had their tools), sealed himself and 25 others behind a bulkhead made of timbers and their own clothing, while J. D. Moore, a shift boss, did the same with seven others. Even though oxygen – and time – ran out for some of the men most of them in these situations survived. Duggan was among them, but he ultimately succumbed to the toxic gases when he returned to the shaft to look for lost companions.

Throughout the ordeal, both men wrote to their wives, including Duggan’s missive: By the time all the men were rounded together Friday night we were all caught in a trap. I suggested we must build a bulkhead. The gas was everywhere. We built a bulkhead and then a second for safety. We could hear rock falling and supposed it to be the rock in the 2400 skip chute. We have rapped on the air pipe continuously since 4 o’clock Saturday morning. No answer. Must be some fire. I realize the hard work ahead of the rescue men. Have not confided my fears to anyone, but welcome death with open arms, as it is the last act we all must pass through, and as it is but natural, it is God’s will. We should have no objection.

A Labor Dispute

The incident ignited a simmering labor dispute. Grievances against the Anaconda Copper Mining Company and conflict with the Industrial Workers of the World (IWW), a socialist organization that effectively crushed the unions several years prior, made the timing right for a fight. The Speculator Mine disaster was all it took to incite violence, including lynchings, resulting in calling in federal troops and the passage of the Montana Sedition Act, which clamped down on any speech or actions contrary to the war effort. In the end, workers received few benefits, while the unions never regained their full power.

From Underground to Open Pit Mines

After WWI, underground mining shifted to more expedient open-pit mining. Created in 1954 by the Anaconda Company, the now infamous Berkley Pit, absorbed entire suburbs as the company expanded the operation. When copper prices fell in the early 1980s, the new owner, Atlantic Richfield Company (ARCO) ceased operations. In 1983, they removed equipment and shut off the water pumps, creating the now 1000-foot-deep, highly toxic, lake.

Ironically, the same metal-laden, acidic water that eats metal flooded the world beneath the town and provides an unusual benefit. Jaap said, “Actually, the water preserves (the timbers), but it makes (the mine shafts) inaccessible.”

The Berkley Pit is now a Superfund Site and a must-see point of interest in Butte, but mining still is the heart of the town. Jaap said the Continental Pit, the former location of Columbia Gardens that once provided a green respite for Butte families, is where silver, zinc, and copper are mined.

A lot of things we do today have a cost,” said Jaap. “For Butte, it’s really visible.”

Residents are proud of their heritage of bringing these important minerals to the world. “The Butte people and their families worked really hard and they take pride in it,” said Jaap. And well they should.

This story about the Butte, Montana, previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Amy Grisak. Photos courtesy of the Butte-Silver Bow Archives.

The post Butte, Montana: Copper Mining first appeared on Rock & Gem Magazine.

For instance, the Finger Lakes region of central New York is known as “wine country” but one of its unexpected collectibles is the lake beach glass, sometimes still faintly bearing the etched lettering of its origin story, found with particular prevalence along the eastern side of Seneca Lake at Lodi Point Beach State Park.

Why? Old wine bottles: Castaways of vineyards past.

But rarer still are the ancient maritime castaways of ale and rum bottles from the Golden Age of Piracy (1650-1730), known as “pirate glass,” that wash up on the beaches along the Caribbean, North American eastern seaboard, West African, and Indian Ocean shipping lanes and trading ports.

Such Shanghai surprises tantalize collectors but not every dark piece tells the same story. Because, as Captain Jack Sparrow liked to say, “Not all treasure’s silver and gold, mate.”

Sea Glass Color – The Dark Side

Pirate glass is colloquially described as “black” but the intensity of what is more likely to be blue, brown, green, purple or red glass has been deepened by the addition of cobalt, copper or iron oxides; or during the glass-making process, the addition of iron slag, or coal and wood ash.

Why darken glass? To extend the life of products and their transport because darker glass protects valuable liquids (like alcohol or oil) from degeneration by sunlight.

The same properties added to deepen color also improve the structural integrity of the glass and make it less likely to break during handling and storage.

At sea, water may turn too contaminated to drink, but not ale or rum. Or a seafaring elixir of lime, sugar and rum often kept aboard in dark bottles as a survivalist measure against scurvy.

The strong, dark glass was perfect, beachcombing blogger Kirsti Scott notes, “For pirates on seafaring ships!”

Stones & Scallywags

Black joins gray, orange, teal, turquoise, red and yellow as the seven most difficult sea glass colors to discover. Pirate glass looks black but not all black glass is old enough to truly be “pirate.”

Well after the 17th-century heyday of pirate ships, early 19th-century decorative black glassware, known as Black Amethyst, was produced, as were black glass buttons to accent Victorian French fashion and, in more mundane industrial use, for light bulb insulators produced in plants like the General Electric and Vitrite Company in Ohio.

Slag Glass

Vitrite also happens to be the name of the slag glass often used as a dielectric, or electrical insulator, at the bottom of common light bulbs and consisting mainly of ground glass with “copious amounts of lead and manganese oxides, the latter being responsible for the dark purple color.”

In fact, Black Amethyst has become its own desirable sea glass collectible, with pieces more than 80 years old washing up along the Great Lakes and particularly Lake Erie, where these incandescent light bulb plants operated.

Still, other black beach glass pieces can be found downstream of defunct glassmaking factories, the remnants of bars or nuggets used to colorize clear glass. Also, blue-black glass traces to gin bottles from Holland, and red-black glass to Portugal.

While no less lovely to look at or bring home, these glass pieces lack the unique merits to claim provenance beneath the Jolly Roger.

Ahoy, Pirates

What helps qualify a piece of black sea glass as “pirate glass” is age (glass from the mid-17th century was hand blown) and location (albeit not all seafaring routes had to be Caribbean).

Pirate glass is noteworthy for its size, for the number of bubbles trapped inside its glass, and for its primitive density that (when held up to light) can reveal a “glow” along the edges of its true dark amber, olive green, or purple color. Older pieces may be so dense and opaque that light will not shine through them.

“Pirate ships were no strangers to the shores of the Outer Banks [of the Carolinas], and neither were their rum bottles. After hundreds of years of these bottles being tossed around by the sometimes extremely violent and vicious waters of Hatteras Island, these black chunks occasionally appear on the shore, to a beachcomber’s delight,” collector Kristin Hissong recounted in 2020 for the Island Free Press.

Knowing What to Look For

The trick is knowing what you’re looking for because pirate glass, by virtue of its dark color, blends almost too well into a beach’s natural background and can look a lot like any other average black stone.

“The first time I found a piece of pirate glass,” Kristin says, “I was going back and forth over one little shell bed gathering other treasures. When I first noticed the piece in the sand, I dismissed it as asphalt. It was about four inches long and looked like a black chunk of NC Highway 12.

“I didn’t know sea glass could be so big or so dark. But right before I decided to leave, I thought I might as well pick it up, and to my delight, it was a huge chunk of black sea glass.

“When I held it up to the light, it glowed a deep olive green and the glassmaker’s breath was caught in an air bubble inside the glass,” she noted.

“Ahoy matey, we found Pirate Glass!”

This story about sea glass color previously appeared in Rock & Gem magazine. Click here to subscribe. Story by L.A Sokolowski.

The post Black Pirate Sea Glass Color first appeared on Rock & Gem Magazine.