What is the difference between a mineral and a rock? A rock is an aggregate or mix, of one or more minerals. Here are some fun facts about minerals to enjoy…

René Just Haüy

2022 was the bicentennial of the death of René Just Haüy (2/28/1743 – 6/3/1822). Not a name many of us know, but Haüy was a French mineralogist and is important because he is known as the Father of Modern Crystallography. He studied crystal structure, applied his theories to mineral classification and wrote several books including the Traité de Minéralogie.

To honor him and the importance of minerals in our world, the International Mineralogical Association named 2022 the Year of Mineralogy.

What are Mineralogy & Crystallography?

Mineralogy is the study of everything about minerals including their crystal structure, physical and chemical properties. Crystallography is the study of the structure and properties of crystals.

How Minerals Are Formed

Minerals are formed in four main ways:

• From Magma – Hot, molten lava cools and crystallizes to form minerals such as topaz.
• From Water – Chemicals in saturated water precipitate, or separate, into solids. An easy example is salt, halite, that’s left behind after ocean water evaporates.
• Alteration – As minerals react, slowly or quickly, with their environment they form different minerals. Cuprite forms when it’s exposed to oxygen.
• Metamorphism – Exposure to heat and pressure alters the chemistry of a mineral to become a different mineral such as rubies.

Glorious Gemstones

Gemstones used for jewelry can be considered at the top of the mineral world. They are rare, valuable, popular and prized for their mineral colors which can be quite vivid once they are cut and polished.

FYI – Not all gemstones come from minerals, for example, pearls and amber. Gems can be precious meaning they are the rarest and most valuable. There are only four precious gems; diamonds, rubies, emeralds and sapphires. Gems that are also popular for jewelry but not as rare are called semiprecious…think amethyst, agate and turquoise.

The rating of precious or semiprecious was made long ago. Today, some semiprecious stones can be worth more than precious stones. Also, it doesn’t take into account scientific classifications of minerals. For example, emeralds are a type of beryl. Aquamarines are also a type of beryl.

Fabulous Diamonds

The word diamond comes from the Greek word adamas which means “invincible.” That’s certainly an accurate description given that diamonds have a Mohs hardness of ten!

According to National Geographic Kids Weird but True Rocks & Minerals, “On Earth’s surface, diamonds are rare. But go down around 100 miles below the surface and it’s a different story. Some scientists have estimated there may be more than a quadrillion tons of diamonds locked in rocks in Earth’s interior.”

This story about celebrating minerals appeared in Rock & Gem magazine. Click here to subscribe. Story by Pam Freeman.

The post Celebrating Minerals first appeared on Rock & Gem Magazine.

Identifying the Risks of Radioactive Minerals

Understanding which parts of your collection may pose a risk is the first step. You might have just a few individual, radioactive mineral specimens. But some large rocks may also contain an amalgamation of multiple types of potentially radioactive minerals. In addition to these radioactive minerals, there are also daughter products that are created as the result of radioactive decay. Daughter products, such as radium, radon gas and uranium, are themselves radioactive.

According to Alysson Rowan, author of Here Be Dragons or The Care and Feeding of Radioactive Mineral Species, some radioactive minerals may even be hiding in plain sight. “A specimen that doesn’t look very good because it’s not well crystalized — somebody may cut that into a decorative stone and mount it for wearing,” Rowan says. “You can find these things on sale, and there’s no mention of the fact that it is radioactive.”

Based in Holsworthy, England, Rowan is also a former radiation safety worker with extensive training in geology. She continues, “There’s no mention that this is not something that you would want to wear, so, people buy these things and wear them in ignorance.”

Detection Equipment

Because uranium minerals tend to be very colorful, they’re among the most popular with collectors. “The other thing is that there are a lot of them that are fluorescent,” Rowan says. “With uranium minerals, you tend to get greens and yellows, but there are minerals that glow blue, and red, and I think there’s even one that’s now known to fluoresce purple.”

Incidentally, to test the radioactivity of your stash, you’ll want to purchase a handheld radiation detector. “If they’re going somewhere to collect uranium minerals or they expect to find uranium minerals, a handheld ‘Geiger counter’ is a must-have,” Rowan suggests. “Of course, they’re not all Geiger counters now. . . . A lot of them are scintillators which are a lot more sensitive and a lot more durable. They generally show how much radiation they’re detecting either on a meter or on an alphanumeric display.”

You can also find used Geiger counters for sale online. “A lot of people buy them second-hand on eBay,” she says. “The American Civil Defense monitors are very, very popular because there’s a lot of them about.”

Saléeite and autunite are two colorful — and radioactive — minerals. “In bright sunlight, you can see the fluorescence,” Rowan notes. Both are in the bright yellow-green range.

Just don’t get too attached to that autunite, as it will literally disintegrate. “Autunite is what’s known as a metamict,” Rowan explains. “It decays radioactively, and the radiation damages the crystal. Inside a few years, it’s just a pile of dust. . . . And, so, autunite will actually spread all over the place.”

Radiation Effects

Containing that radioactive spread is paramount because the negative effects of radiation on the body are cumulative. In other words? The radiation you absorb builds up over time. You can inadvertently expose yourself to radiation internally by absorbing contaminants through your skin. You can also inhale or ingest radioactive contaminants.

The acute effects of radiation exposure can range from erythema — akin to a deep tissue sunburn — to renal failure. “The uranyl minerals—that is uranium oxide as a radical—are toxic to your kidneys,” Rowan says. “So, that is what you’ve got when you pick up most fluorescent minerals. It’s uranyl phosphates, uranyl nitrates—they are highly toxic.”

Over the long term, exposure to some radioactive compounds can even result in bone cancer and leukemia. In her book, Rowan writes, “Inhaled uranous and thorium compounds, and to a lesser extent the uranyl compounds will result in both toxic and radiation damage to the lung. Long-term effects will include bronchitic and emphysema-like symptoms as well as a range of pulmonary and pleural cancers.”

Smoke Alarm

Keeping cigarettes, incense, and other smoky stuff away from radioactive specimens is especially important.

For safety’s sake, you should never eat or drink while handling radioactive minerals. Applying a quick smidge of lip balm’s another no-no. And smoking is right out, too.

“The thing about smoking is one thing that you do is that you handle the rock and you put your cigarette to your mouth and you’ve immediately got rock dust on your lips,” says Alysson Rowan, the author of Here Be Dragons or The Care and Feeding of Radioactive Mineral Species.

What’s more, let’s say some of your specimens contain uranium. As uranium goes through its multiple stages of decay, it eventually releases radioactive radon daughter products and radon gas. “The airborne activity from radon daughters and radon gas itself will attach themselves to smoke,” Rowan continues. “So, when you re-inhale smoke, you’re inhaling the radioactive contaminants in the atmosphere.”

In her work, Rowan writes, “It has been noted that the presence of blue smoke from cigarettes (the plume that rises from the burning tobacco) collects the radioactive radon daughter products more surely than any other means of concentration. This means that the spent smoke you breathe in a high radon concentration area is bringing those radioactive materials into your lungs in a form which tends to remain inside your body.” Such radiation exposure in the human body is cumulative. Rather than dissipate, the radiation exposure adds up. “The consensus of scientific opinion is that a given dose from radon is possibly 10 or 15 times as dangerous to a smoker as to a nonsmoker,” Rowan notes. To mitigate this risk, never smoke in areas where you keep radioactive specimens.

Minimizing Exposure

Although different minerals pose differing degrees of risk, if you are pregnant, you should avoid contact with radioactive minerals altogether. As for young children? “Before puberty, we are a lot more susceptible to radiation damage because of the rapid cell division,” Rowan says. “Children should not be around. . . radioactive minerals more than absolutely necessary for their study.”

There are several precautions you can take to minimize your overall radiation exposure and still appreciate the radioactive specimens in your collection. Besides the degree to which a mineral is radioactive, the amount of the mineral in question matters as well as the cumulative amount of time that you spend in direct contact with it.

“If you sit with a pound of uraninite using it as a paperweight on your desk, that is going to give you a problem eventually,” Rowan maintains. “If, on the other hand, you have that pound of uraninite and it’s in a lead-acrylic case, that reduces the dose rate and, therefore, it’s not quite the same problem.”

Display Do’s and Don’ts

“You also have to take into account how far you are from that specimen,” Rowan adds.

When you increase the distance between yourself and the specimen, you decrease your potential radiation dose. Adding shielding materials like lead, wood or glass can further reduce your radiation exposure.

“For the most part, you put [your collection] on display in a cabinet,” she says. “The idea is that you’re keeping dust off of your specimens, but you’re keeping dust from the specimens fixed.”

Regarding those uranium-rich minerals, keep in mind that uranium decays into radium which, in turn, will decay into radon gas. Because this heavy, radioactive gas can easily migrate, you should air out your uranium mineral display cases periodically. “I’ve done this with my own cabinet,” Rowan says. “You open the cabinet and stick your [radiation] meter in and the radiation count goes up. And, over about half an hour, the count rate goes right down, because the radon daughters in there only have a short half-life.”

Still, she cautions, “If you’re a serious uranium collector, then it’s probably a good idea to have vented cabinets—venting to the outside world.”

Also, never store or display uranium minerals in a basement. “Radon gas is an awful lot denser than air,” Rowan explains. “It’s a big atom and it will hang around for a couple of weeks.”

Handling How-To’s

If you do need to handle a radioactive mineral specimen, don’t dally. “If you’re working with it for too long, that’s all additional exposure,” Rowan says. “So, the amount of time that you’re in contact with the rock, you need to minimize it. And you need to make sure that you don’t spread contamination everywhere.”

To that end, she suggests wearing protective clothing and disposable gloves and protecting your work surface with a disposable covering. Washing carefully with soap and water is also key. “If you handle a radioactive rock, you’ve got radioactive rock dust on your fingers and you’ve got to wash it off,” Rowan says.

Finally, to prevent ingestion or inhalation of radioactive contaminants, never eat, drink or smoke when working with radioactive minerals, and, Rowan concludes, “Don’t be paranoid, but do take care.”

This story about radioactive minerals appeared in Rock & Gem magazine. Click here to subscribe. Story by Susan M. Brackney.

The post What are Radioactive Minerals? first appeared on Rock & Gem Magazine.

Minerals are all around us and even within us. Consider iron in your blood or calcium in your bones. While humans have always sought food products, we’ve always used rocks. Our ancestors used cobbles as hammers to crack nuts. We later learned to use obsidian, chert, and flint to knap knives and spear points and to spark fire. We’ve moved on from the Stone Age to the Copper, Bronze, and Iron Ages. Minerals and related earth resources continue to enable contemporary life and the built environment in which we live. They include metals, nonmetallic minerals, and fossil fuels. How little we appreciate this fact of life!

Take the Common Pencil…

Something as simple as a pencil requires more minerals than you might imagine. While a pencil casing is painted wood with a hollow core, the rod within the core is a combination of graphite (carbon) and kaolinite (clay). The more kaolinite, the harder the rod. This is why we have #2, #3, and other pencil grades that leave either a wide dark streak or a slender light streak. While the pencil eraser is a natural or synthetic rubber, it may contain pumice to provide grit. Holding that eraser to the pencil is a tube constructed of aluminum (from bauxite) or brass (from copper plus zinc, or sphalerite). Four to six minerals in a common pencil. Who knew?!

To appreciate the number of minerals used in everyday life, deconstruct other objects. A salt shaker often has an aluminum top (derived from bauxite) and a glass body (from sand, or silicon dioxide) and is filled with salt (halite) crystals. Although it’s on its way out, an old-fashioned incandescent light bulb has a glass exterior (made from silica, soda ash, lime, coal, and salt), a brass or aluminum screw-in base, a tungsten filament, copper and nickel lead-in wires, molybdenum tie and support wires, and an aluminum heat deflector.

Explore Minerals Contributing to the Build Environment

Here are some fun and easy exercises to introduce kids (and yourself ) to the many minerals contributing to our built environment.

Match the Product to the Mineral

An Interactive Display & Quiz

Perfect for a school project…Construct an interactive display showing everyday items at the back and the minerals that went into them at the front. For instance, a soda can at the back and a specimen of bauxite (aluminum ore) at the front, or matches at the back and sulfur at the front. Provide a quiz for kids to fill out to match a mineral to a product.

Spin the Wheel!

For more immediate interactive fun, have a board laid out with squares numbered and stocked with different economic minerals. Kids spin the wheel. They then need to name a product made from a mineral on the number where the wheel lands. If they guess correctly, they keep the mineral. Stick with fairly easy and obvious choices (e.g., a copper nugget matched to plumbing pipes) and have a poster or chart nearby that kids can consult.

The Home Scavenger Hunt

In a school classroom, rock club meeting room, or a home, gather kids around a flipchart, chalkboard, or whiteboard. Encourage them to look around and list everyday things and the rocks and minerals that went into them. If using an old-fashioned chalkboard, you can start with the chalk and the slate of the chalkboard. You might go throughout an entire house, or focus on a particular room.

Here are just a few examples: a brass lamp, windows made of silica, many things made of plastic derived from petrochemicals, fireplace bricks derived from clay (kaolinite), a tin cup, a gold wedding ring, walls made of plasterboard comprised of gypsum, steel nails, and screws in the furniture and paint on the walls containing diatomite as filler.

A Hardware Store Scavenger Hunt

Take a field trip for a scavenger hunt at a hardware store. To get started, here are a few things to seek:

• aluminum and tin siding or roofing (from bauxite or cassiterite)

• bricks and ceramic products (from fired clay, or kaolinite)

• diatomaceous earth for swimming pool filters

• drill bits and saw blades used for cutting tile, concrete, etc. (from diamond)

• electrical wiring, pipes, and plumbing fixtures (from copper)

• glass (from silica sand)

• plaster and drywall (from gypsum)

• rough and crushed rocks and stones for ornamental use (scoria, limestone, marble, etc.)

• sand for mixing with concrete, for sandboxes, etc.

• slabs of various sorts (granite, marble, etc.) for kitchen countertops

• steel and iron nails (made from iron ores like hematite)

Make Your Own Collection

Entire collections can be made of the raw materials of our built environment. Many common minerals are inexpensive and readily available from show dealers. As a start, consider pennies and a copper nugget; nails and hematite; fluorinated toothpaste and a fluorite crystal; laundry detergent and borate minerals; table salt and halite crystals; matches and sulfur.

Learn More!

Several websites provide handy tables linking minerals to everyday objects. Here’s a sampling:

• Minerals Education Coalition

• Women in Mining

• United States Geological Survey (USGS)

• American Geosciences Institute (AGI)

• Gemological Institute of America (GIA)

• National Mining Association

• AFMS Future Rockhounds of America Badge Manual

How Minerals Shape History

As we humans progressed from the Stone Age to the Electronic Age, we’ve seen all sorts of ages in between dominated by a search for earth resources. Consider gold rushes, wars of conquest for mineral-rich colonies, and “titans of industry” (Carnegie, Rockefeller, Peabody, Getty). Our current age is obsessed in a quest for minerals for electric batteries built with lithium, and cobalt. These resources are eagerly being sought to move us from a carbon-emitting petroleum-dependent economy to one based on clean energy.

However, keep in mind that clean electric energy still requires dirty mining. If you think we can get to a so-called no-cost energy future, think again! There will always be a need for mining and minerals, along with a cost to pay. How we ultimately balance such costs is what matters. Think we can live without minerals and all that goes into extracting them? Think again. Think wisely.

What Made It?

Pencils or smartphones are just the beginning. There are thousands of minerals and even more applications of those minerals. Here’s a tiny selected sampling…

This story about the minerals used in everyday life previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Jim Brace-Thompson.

The post Minerals Used in Everyday Life first appeared on Rock & Gem Magazine.

Everything is Energy

While this connection might seem puzzling on the surface, it all boils down to energy. Samantha Fey, author, teacher and co-host of the podcast, Psychic Teachers, said, “Crystals have the piezoelectric effect, so they do generate energy. They grow with their own unique vibration and lattice structures.”

This phenomenon occurs when pressure is put on particular crystals, such as quartz, causing the atoms within the stone to move, subsequently turning mechanical energy into electrical energy. This is why crystals are used in watches, televisions and cell phones. It’s this inherent energy that resonates with astrological signs.

Connecting Zodiac Crystals & Sun Signs

Those who are familiar with astrology understand the correlation with the elements — fire, water, air, and earth — and how they offer a glimpse into personality characteristics. When working with crystals according to sun signs, it’s helpful to consider the elements and how they best fit with the particular stones.

Fey used an example of the sun sign Cancer, which is attributed to the moon and is a classic water sign. “They are very watery and ruled by their emotions. Look for crystals with those similar qualities,” she said, such as moonstone.

It’s also important to understand how a stone works with a particular sign in coordination with where we are physically, mentally, and spiritually. “Our energy fluctuates up and down all the time,” Fey said. Depending on what we need, crystals can amplify or balance our actions.

While there are classic combinations of crystals and Zodiac signs, such as obsidian with those under Scorpio, in reality, there are multiple crystals per sign. The choice depends on what you need to do or learn, and this list is a good start to finding a crystal that works for you.

Aries Sign

Notoriously stubborn, Aries people know what they want and are clear about who they are. Fittingly, amazonite is an ideal crystal for this sun sign as it enhances inner strength and the warrior attitude, particularly with women going through significant changes in their lives.

“It’s called the stone of hope and new beginnings,” said Fey, and is excellent for manifesting dreams and goals.

Deb Bowen, co-host on Psychic Teachers, as well as a metaphysical teacher and author, recommends Sardonyx because it is excellent in the realm of self-control and discipline.

“It’s really good for communicating relationships,” she noted because Aries can have sticking points in this area.

Taurus Sign

An earth sign, Taureans, are grounded people who are nurturing and comforting to those most important to them. Being a bull, they are known for their stubbornness and uncompromising nature.

The beautiful light blue to green, or sometimes white kyanite is good for Taureans because it helps clear and align the chakras, according to Bowen. It also builds stability and trust and is excellent for communication. Kyanite cannot hold negative energy.

Fey recommended, ”Carnelian is a great stone for bringing in creativity, positivity and joy. It’s the cheerleader of the stones and it keeps the other stones together.”

Gemini Sign

When a “twin” is around, there’s never a dull moment. Geminis are known to have lots of energy and are very talkative. They can also be indecisive and impulsive.

The green and smooth gem serpentine is a good fit for a Gemini. “It helps you to align your soul’s purpose,” explained Bowen as it enhances the heart chakra. She noted that it also offers protection against the dark arts.

Cancer Sign

Cancer is the classic mother of the Zodiac who is family-oriented, intuitive, and a tad moody. Not surprisingly, the “crab” is their sign.

Bowen said, “Sometimes cancer folks can get sad or depressed.” Because of this tendency, she said blue chalcedony is a good choice. “It helps cancer to communicate the truth. It also dispels negative energies and activates positive changes. It’s a great stone for those who seek general positive shifts in their lives.”

Leo Sign

Leo is known to love being the center of attention with their bigger-than-life energy. They’re also loyal, generous, and loving. The funny thing is, their negative traits simply seem to be their positive traits on overdrive.

Because of this desire to shine, citrine is the stone for Leos. ”Citrine is like your own personal sun,” said Fey. This yellow-to-orange type of quartz appears charged by the sun. Unfortunately, natural citrine is a rare stone and much of what we find is heat-treated amethyst (enhanced gemstones). It’s also well-known to manifest abundance, a natural quality of Leos, and is sometimes called the “stone of success” or the “merchant’s stone.”

Virgo Sign

Logical and energetic, Virgos thrive with well-organized and practical goals, while on the flip side, they tend to overthink situations and can often seem aloof and detached.

Resembling the blues and greens of the earth, the mineral chrysocolla is often found in copper deposits and referred to as the “Stone of the Goddess,” with famous figures, such as Cleopatra, valuing its beauty and energy.

Fey said chrysocolla is like a happy-go-lucky friend. “It’s a great stone for everything. It helps people face some hard truths,” she said. She also recommended that those working with this stone visualize their goals going into the stone.

Libra Sign

The scales represent Libra’s desire for fairness and balance, which is the center of this witty, smart and outgoing soul. With Venus as their ruling planet, they are all about love but will carry a grudge if slighted.

“Libras look at both sides differently, or rather it’s difficult to choose sides,” said Bowen, who is a Libra. She said bloodstone is good because it balances everything, including Libra’s energy. “It helps level folks be present in the here and now.”

Scorpio Sign

Scorpios get a bad rap as being secretive, defensive and vindictive, but their emotions run deep (even if they don’t show it), and they are passionate about whatever, and whoever, they love.

“Malachite is the drill sergeant,” said Fey. “It’s the only stone that breaks to warn you when something wicked this way comes. It’s great for protection.” This rich green stone is also an important part of facing Scorpio’s shadow side. Fey said, “It’s like a friend that is in your face.”

Known as the stone of transition, Bowen said, “Charoite connects the heart and crown chakras.” It allows someone to focus on self-love when setting healthy boundaries.

Sagittarius Sign

Ruled by Jupiter, Sagittarius people are gregarious and big dreamers but can be blunt and preachy.

Fey recommends labradorite that resembles the aurora borealis with its color-shifting nature where one moment it looks gray, the next is shimmering blues and greens. “It helps block the emotions and stuff around you that’s not yours. It’s more like a filter. It lets the good stuff come in and the bad stuff goes out,” she said.

Capricorn Sign

With Saturn as the taskmaster, Capricorns get things done. Although they are disciplined and responsible, this can shift into a level of condescension toward others.

Amethyst is the go-to for these hardworking signs. “It cleans, clears, and heals everything around it,” said Bowen. ”It’s a balancing, protective and loving stone. It’s a great stone to connect. It fights off temptation and works with decision-making. It’s good for sleeping and it protects them from nightmares.”

Once used by the Romans to fend off the evil eye, tiger’s eye is protective and balancing. Fey said, “It works with your energy to establish a foundation and recognize patterns of things that no longer serve you. She said to place tiger’s eye on the solar plexus during meditation for courage and confidence, as well as to shift toxic energy into positive ones.

Aquarius Sign

Quirky and unconventional, the highly social Aquarians champion humanitarian efforts and relish deep conversations. Yet, they are not known for being the most emotionally open individuals and might appear aloof.

“Aquarians are ahead of their time,” said Fey. “Dark, ruby red garnets help them recharge and revitalize their energy. Write down goals and dreams for the year and place garnets on top of the list.”

The ornamental chrysanthemum stone is typically all black except for a splash of white in the middle resembling a flower. Bowen recommended it for Aquarians because ”it brings to us child-like energy and being able to live in the moment.”

Pisces Sign

The astrological fish who swim in deep waters are philosophical, intuitive and creative, yet at times, spend too much time in their own heads.

To counteract this latter tendency, aquamarine, which is often called the “stone of courage” boosts confidence for the Pisces people. Bowen said, “It’s such a beautiful stone. It helps one to always be prepared.” Legend says aquamarine was spilled from a mermaid’s treasure chest and it was supposedly blessed by Neptune.

Fey recommended fluorite to clear negative energy. Called the student’s stone, she said, “It’s created for cleansing the aura. It eliminates negative patterns and helps you to see your path more clearly,” said Fey. She also mentioned it is effective in blocking electromagnetic fields and is often kept near the computer to minimize exposure.

Picking the right stone for you is a matter of listening to the universe. “It’s really important when you buy sun sign crystals that the stone speaks deep, deep into your soul,” said Bowen.

“It’s great to read and study, but at the end of the day, you have to go with the crystal that resonates with you,” noted Fey. “Walk into a store that sells stones and see what you’re drawn to. Find your buddy and stick with it for a while.”

*The metaphysical properties discussed in this article are not intended as a substitute for traditional medical treatment. If you have a health issue, please seek a licensed medical professional. The crystals and stones discussed are not intended to diagnose, treat or cure any conditions.

This story about zodiac crystals previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Amy Grisak.

The post Best Crystals for Your Zodiac Sign first appeared on Rock & Gem Magazine.

When the war ended, mines powered down, leaving countless miners jobless, miners who knew the underground workings and minerals without an opportunity to use their skills. Surplus war materials like Jeeps were sold and military veterans, among others, combined the availability of four-wheel-drive vehicles with the opening of more federal lands and headed into the great outdoors, and the mineral collecting hobby grew rapidly. This rapid growth created a ready market for minerals, which prompted Mexican miners to go back to work, with some even forming mineral collecting consortiums.

Mexican Rocks & Minerals in High Demand

Instead of mining metal ores, the miners mined mineral specimens of every variety. Mineral dealers located close to the border became a ready market for access to minerals from Mexico. As miners realized they could make a living underground, the flow of minerals from Mexico’s mines became a flood by the early 1950s.

The volume of minerals coming out of Mexico was so great that some dealers became wholesale marketers operating in or near border towns like El Paso and Tucson. This interest provided Mexican miners a ready outlet for their efforts. In a short time, dealers and collectors began driving to Mexican mining towns to buy directly.

Wholesale dealers like Tucson’s Susie Davis sold minerals by the flat and never lacked good stock. Miners catered to visitors but always kept the better specimens under the bed. People who visited the Tucson Show by 1960, especially show dealers, planned ahead and drove to Mexico after the show to restock.

Today, with the growth in illegal activities and a slowdown in mining, the halcyon days of rockhounding in Mexico are more past than the present. Solo trips are less encouraged than in years past.

Mina Ojuela

In spite of some difficulties collecting in Mexico today, there are still plenty of fine Mexican minerals available, which is a testament to the huge quantity of specimens that poured forth in the last half of the 20th century. Miners are still working underground, and once in a while, a big hit happens.

Among the most active mines during the heyday was Mina Ojuela, Mapimí, Durango. It is credited with producing some of the world’s finest examples of species like adamite, legrandite, and koettigite. It soon became the darling of Mexico’s mineral business 50 years ago, along with Santa Eulalia, Zacatecas, and San Luis Potosi. There are several mines around Mapimi, but Ojuela was the first in the Durango area. Over time, underground tunnels eventually interconnected the mines, so a miner might be digging in one mine but credit his find to Ojuela often to keep secret where he actually found the minerals.

Mina Ojuela’s Specimens

Mina Ojuela was discovered in 1598 by Spaniards looking for riches. The ore vein they spotted was high on the wall of a limestone canyon, which created a problem. Reaching the ore was tough enough, but to actually mine the ore presented a major elevation challenge and an amazing feat of effort.

Mina Ojuela’s reputation as a specimen producer is due to the number of species it produced. The variety of species reads like the index of a mineral book. Until Mina Ojuela, adamite was a non-descript hydroxide zinc arsenate of modest color and crystal size.

The type locality was Chañarcillo, Chile. The ancient silver at Lavrion, Greece, produced decent adamite as well, but it was not until the brilliant green crystal sprays of adamite from Mina Ojuela came out in huge quantities that adamite was a must-have mineral. Its crystals are in a fan-like shape or fat ball-like crystal clusters, single crystals and sprays all on a contrasting dark brown iron oxide matrix. The quantity found here was astounding.

Another mineral found at Mapimí is olivenite, hydrate copper arsenate. The only difference between olivenite and adamite is the metal within; in one, it’s copper, and the other, zinc, which are compatible and can easily replace each other. Adamite is green thanks to a trace of copper in it. When copper replaces even more zinc, it is cuproadamite. Russian scientists went further in 2006 and found that if enough copper replaces zinc in some cuproadamite, it forms a new species, zincolivenite. Is your cuproadamite really zincolivenite? Ask Mother Nature.

Mexican Rocks & Minerals

The specimen-producing mines of Mexico are all known. The Spaniards started them out as silver mines and some produced wonderful silver sulfosalt minerals like acanthite, polybasite, tetrahedrite, tennantite and bournonite, all collector minerals. These same mines did not gain a reputation for producing native silver specimens except for Batopilas mine, Sonora. The vast majority of the silver mines had the metal argentiferous galena, sulfosalts, and other collector minerals in the deposits. These old Spanish silver mines became major sources of fine collector minerals for decades in the 20th century as local miners became skilled mineral specimen miners.

The Batopilas mine, Chihuahua, produced fine native silver specimens in some quantity when opened in 1632 by the Spaniards, who found the local native people working it. Even today, this mine is known among collectors for its fine twisted wires and crystals of silver. Spaniards were only interested in mining the silver, so other minerals were bypassed, leaving them for collectors who followed.

Sonora & Chihuahua

Each of Mexico’s states is known for a particular mineral species. Sonora is famous among the lapidary crowd for agate. Among collectors, wulfenite from Sonora and nearby Chihuahua is well known. Chihuahua was made famous by National Geographic in 1921 when it featured the giant selenite crystals in the Cave of Crystals/Cave of Swords. It revisited the site again in the 1990s. This second visit was broadcast on television as the selenite cave had the world’s largest selenite crystals — 40 feet long!

Zacatecas & San Luis Potosi

The state of Zacatecas has certainly produced superb collector minerals including azurite, galena, sphalerite, chalcopyrite and other metal ores. And, of course, silver species and gold have also come from here.

San Luis Potosi is very well known among collectors due to the superb poker chip calcite specimens it yielded in recent years. These specimens rival the historically important calcites from Germany. Quantities of large and sometimes colorful danburite crystals still come from here now and then as well.

Sinaloa

In recent years, Sinaloa really caused a stir among collectors when the mine at Choix produced large quantities of colorful botryoidal smithsonite. Specimens up to a foot across were mined, and the color range seemed endless, from white to pink to yellow, blue, and green in various tints. Many of the Chiox smithsonite was easily mistaken for the famous blue specimens from Kelly Mine, New Mexico.

The range of collector minerals from Mexico in the last 75 years is simply amazing. From gorgeous Las Vigas amethyst crystal groups to recent Milpillas mine azurites to rare silver sulfosalts and everything in between, these finds enhance mineral collections worldwide.

The millions of mineral specimens brought to grass in Mexico have played a huge role in the growth of this hobby throughout the world in these last decades, and there is no end in sight.

This story about Mexican rocks and minerals previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Bob Jones.

The post Mexican Rocks & Minerals Collecting first appeared on Rock & Gem Magazine.

“A diamond is forever,” the classic advertising slogan of the De Beers Diamond Syndicate, refers to both the durability of diamonds and to the love relationships they represent. While scientists don’t profess to be experts on matters of the heart, they do know about gemstone durability, especially the Mohs Scale of Hardness. And considering recent scientific revelations, the diamond slogan could be rewritten as “a zircon is forever.”

Zircon the Gemstone

Zircon (zirconium silicate, ZrSiO2) consists of silicon, oxygen and zirconium. With its wide range of colors and substantial hardness (Mohs 7.5), zircon has served as a gemstone since antiquity. Some biblical scholars suggest that zircon was among the 12 gemstones in the sacred breastplate of the high priest of the Israelites that dates to 1450 B.C. In later medieval times, zircon was thought to promote sleep and bring prosperity, honor and wisdom to its wearers.

The most common of zircon’s many colors is brownish-red. Yet it was blue zircon that enjoyed great popularity in Victorian-era jewelry. By 1900, colorless zircon had become the preferred diamond simulant, thanks to its high index of refraction (1.92-1.96) that gives properly cut zircon gems a fiery, diamond-like glitter. To add to zircon’s gemological credentials, several large, reddish stones are included in the British Crown Jewels collection. Zircon is the birthstone for December.

Nevertheless, as a gemstone zircon does have an image problem. Unlike ruby and emerald, it lacks a dominant identifying color. And because of its previous role as a diamond simulant, zircon is still associated with imitation. Furthermore, zircon is often confused with the modern diamond simulant cubic zirconia (CZ), which is not zircon at all, but a stabilized, synthetic zirconium oxide.

Zircon and Uranium

Because of a mutual chemical affinity, zircon usually contains traces of the radioactive element uranium. The uranium atom’s unstable nucleus undergoes continuous atomic decay, emitting ionizing energy as particles and rays while disintegrating into a series of unstable isotopes that eventually ends with the stable form of lead.

Uranium’s radioactivity causes some zircon crystals to undergo metamictization, which occurs when radiation displaces electrons within the zircon lattice to slowly degrade the crystal structure. The effects of metamictization include rounded crystal edges; curving faces; separating cleavage planes; color alteration; and decreased hardness, density and transparency.

Metamictization can sometimes degrade transparent zircon crystals into opaque, amorphous masses. However, metamictization is not a problem with zircon gems. Radiation levels are far too low to be hazardous and the physical effects of metamictization in zircon become apparent only after millions of years.

The “Clock in the Rock”

The marriage of zircon and uranium makes possible very long-term radiometric dating. Rates of atomic decay are expressed in terms of “half-life,” the time in which radioactive isotopes lose 50 percent of their radioactivity. The uranium-238 isotope has the longest half-life at 4.5 billion years.

When igneous rocks solidify from magma, uranium is often present in their compositional minerals. Because atomic disintegration progresses at known, precise rates, measuring the ratios of the decay-chain isotopes reveals the extent of atomic decay and thus the time that the mineral crystallized.

To date extremely old materials, uranium must be trapped within an extraordinarily durable, abundant and widely distributed crystal such as zircon. Zircon is inert and insoluble, while its crystal structure assures survivability even in the high pressures associated with geological upheaval and burial. It’s very high melting temperature enables zircon to endure even the extreme temperatures of high-grade metamorphism.

Zircon can survive billions of years of physical and chemical weathering, transport, and redeposition, while its traces of uranium steadily tick away as the clock in the rock.

The Hadean Time Capsule

Geophysicists have radiometrically dated tiny zircon crystals from Western Australia’s Jack Hills to 4.404 billion years. These crystals formed during the Hadean Eon (4.6-4.0 billion years ago), the earliest and least understood of the Earth’s geological time divisions. The Hadean Eon was named decades ago when scientists believed that volcanoes and lava fields dominated the primordial Earth and created “hell-like” conditions unsuitable for life.

But data obtained from the Jack Hills zircon crystals paints a radically different picture of the Hadean landscape, one where the Earth’s crust formed much earlier than previously thought. Furthermore, the ratios of oxygen isotopes trapped within these zircon crystals indicate that an atmosphere and oceans already existed and that life was therefore already possible.

The Jack Hills zircon crystals were originally part of a granitic rock that completely weathered away. These crystals then mixed with sediments that lithified much later and metamorphosed into the 3.3-billion-year-old quartzite-conglomerate formation that geologists call the Jack Hills Quartzite. Polished slabs of this orange-brown meta conglomerate with their tiny reddish zircon crystals are now sold at gem and mineral shows and online.

So while diamonds might be “forever” in matters of love, when it comes to the radiometric dating of the early Earth’s oldest known crustal fragments, it seems that what is forever are zircons.

This story about what is zircon previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Steve Voynick.

The post What is Zircon? first appeared on Rock & Gem Magazine.

What’s in a Firework?

Fireworks have an outside shell that’s called a mortar. It can be made of many things including cardboard, papier-mache or plastic.

Inside the mortar are compartments. The bottom compartment is filled with black powder (potassium nitrate, charcoal and sulfur) that will be the fuel for the firework.

The top compartment contains the pyrotechnic stars that make the colors and shapes we love to see. The stars are made of a fuel that burns and minerals and metals pressed together provide the color. The way the stars are arranged in the mortar provides the shape of the firework, like ovals, stars or rectangles.

Lighting the Fuse

While today’s fireworks have gotten more technical, a basic firework still contains just two fuses. There’s a fuse hanging from the firework.

That’s what is lit first. The firework flies into the sky and as the burning fuse reaches the bottom compartment, it ignites an internal fuse that makes the mortar explode.

Firework Colors

These colors come from single minerals and metals:

Blue is provided by copper (Cu) from chalcopyrite.

Green is provided by barium (Ba) from barite.

Red is provided by strontium (Sr) from celestite.

Yellow is provided by sodium (Na) from halite (rock salt).

These colors are made by mixing minerals and metals:

Orange = strontium (Sr) + halite (Na)

Lavender = strontium (Sr) + copper (Cu)

Silver = titanium (Ti) + zirconium (Zr) + magnesium (Mg)

Firework Effects

Firework colors, sizes and shapes are dazzling, but the special effects step up the game. Here are a few favorite effects and the minerals that make them.

Iron Filings (magnetite and hematite) + Charcoal = Gold Sparks Aluminum Flakes = Flashes Showering Down Aluminum Powder (bauxite) = Loud Bangs & Bright Flashes

Fireworks Road Trip

You can visit the world’s largest geode on Put-in-Bay Island in Ohio. There you descend 40 feet into a beautiful geode made of celestite, a strontium sulfate mineral and the source of the red color in fireworks. The geode is located at Heineman’s Winery and was discovered in 1897 while digging a well for the winery. It saved the winery during prohibition as the winery couldn’t sell wine, but could sell tours of the geode. The blueish-white celestite crystals vary in size from mere inches up to three feet wide. The interior of the original cave was much smaller, but some crystals were mined over the years.

Fireworks in History

Fireworks were made out of paper or bamboo in China 2000 years ago. They weren’t the beauties we have today. They produced only a flash and smoke when ignited.

The shape of modern fireworks mortars is similar to an ice cream cone. This mortar shape was started by the Italians in the 1830s. Credit also goes to the Italians for the invention of colored fireworks.

Be Careful!

Fireworks are beautiful, but they are also dangerous. If you are a kid, never handle fireworks alone!

Each year injuries to kids and adults are reported from accidents with fireworks. Be sure to leave fireworks to the grown-ups to handle. Best yet, go with your friends and family to enjoy a fireworks display and leave the danger to those trained for it.

This story about how do fireworks get their color previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Pam Freeman.

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The three specimens considered by most as the world’s finest rhombic rhodochrosite specimens were displayed at the Rock Summit Show in Denver in 2020. The exhibit was labeled “Rhodochrosite Royalty.” Each specimen has a story to tell…

The Alma Queen

The smaller Alma Queen was collected in the 1960s by a rockhound miner who sold it at a show in Los Vegas. The specimen was sold and passed through several hands until it was obtained by noted collector/dealer, David Wilber.

I saw this smaller Alma Queen at a Tucson Show in the 1970s where Dave had it on display. At the time, it was known as “Wilber’s rhodochrosite.”

Colorado collectors had not seen anything like this specimen from the Sweet Home mine and some of them made a serious specimen mining effort at the Sweet Home but were only marginally successful.

Finding the Original Digger

I had collected in the Sweet Home mine in 1957 with no luck, so I wanted to track down the fellow who dug the Alma Queen. I found he was in New Mexico, so Carol and I visited him there. He was more than willing to tell us how he found the rhodochrosite, but the mine was claimed so he would not allow me to photograph him, tape-record him or even use his name. It’s a promise I still honor.

We had a nice visit and he told us the whole story of finding the specimen and how he sold it in Las Vegas.

After a couple of days of digging, he had opened a seam that produced small rhodochrosite crystals and then he hit the Alma Queen. He was hoping the vein would open up even more and planned on continuing to dig, but a friend of his showed up and said the sheriff was coming to chase him out.

Selling the Alma Queen

He left and later planned to sell it in Las Vegas for a big show there. His asking price was $5,000. He ran into Ed Swoboda, a well-known dealer/miner, and settled on a price. Ed bought the rhodochrosites including the Alma Queen.

Ed eventually sold the specimen to someone in Texas but David Wilber had already seen the Alma Queen, as yet unnamed, and wanted it. He tracked down the specimen in Texas and was able to buy it. Dave exhibited the specimen in Tucson where Colorado collectors saw and called it “Dave’s Rhodochrosite.” That exhibit is what caused later successful mining at the Sweet Home mine that brought to light the Alma King and the Alma Rose.

This story about rhodochrosite and the Alma Queen appeared in Rock & Gem magazine. Click here to subscribe. Story by Bob Jones.

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A Smelting Flux

Fluorite’s association with silver and lead ores first brought it to the attention of Roman miners. They found that it improved the smelting process by reducing melting temperatures while combining with impurities into an easily removable slag.

German smelter workers of the 1500s also used fluorite, then known as Flusse or Flusspat, as a smelting flux. In his classic “De Re Metallica,” German scholar Agricola (Georg Bauer) detailed the use of Flusspat, which he called “lapides igni liquiscentres.” This translates to “stones that become liquid in fire.” Agricola also referred to the mineral as Fluere from the Latin fluor meaning “to flow.” This is the origin of our modern word, fluorite.

Etching Glass

Glass was thought to be impervious to all liquids until 1670 when a German glassworker mixed ground Flusspat with sulfuric acid in a glass container. The glassworker was astounded when the glass dissolved. The glass-dissolving agent was a secondary acid that became known as Flusspatäure, literally “acid of Flusspat.”

The ability of Flusspatäure to etch glass brought new creativity to the art of glassmaking. More importantly, it indicated to chemists that both Flusspat and Flusspatäure contained an active, unknown element. The identification and isolation of this element became the goal of leading scientists for the next century.

The “Fluorine Martyrs”

Although not yet isolated, this mysterious element was named in 1813. French physicist, André-Marie Ampère, acknowledged the element’s hazardous nature. He proposed the name “phtor,” which is the Greek word for “destructive.” English chemist Sir Humphry Davy adhered to tradition and coined the word “fluorine” from the old Latin fluor. In 1826, scientists adopted the words “fluoride” for fluorine-containing compounds and “hydrofluoric acid” for Flusspatäure.

Unfortunately, chemists seriously underestimated the dangers of fluorine. More than a dozen researchers lost their health or their lives by inhaling or contacting elemental fluorine or fluorine-based vapors. They became known as “fluorine martyrs.”

In 1886, French chemist, Frederick Henri Moissan, isolated pure fluorine by electrolytically reducing a mix of hydrofluoric acid and potassium fluoride. He then demonstrated that the yellowish gas was the most chemically active of all elements. His work earned the 1906 Nobel Prize for chemistry. But Moissan paid dearly for the honor, dying a year later at age 55, the last of the fluorine martyrs.

From the A-Bomb to the Present

During World War II, large quantities of fluorite from the Illinois-Kentucky Fluorite District were shipped with false bills of lading via circuitous routes to nonexistent destinations to confuse any possible Axis spies. The fluorite’s true destination was a top-secret facility in Tennessee, where it was converted to elemental fluorine. It was then converted to uranium hexafluoride gas for the separation of the fissionable uranium-235 isotope needed to make the atomic bombs that ended World War II.

Fluorite (calcium fluoride, CaF2) crystallizes in the isometric system and has a Mohs hardness of 4.0, a specific gravity of 3.18, and perfect, four-directional cleavage. It often occurs in hydrothermal veins and is a common gangue component of the sulfide ores of lead, zinc and silver.

Today, seven million metric tons of fluorspar (the commercial term for impure fluorite) are mined worldwide each year. Half is converted to hydrofluoric acid, a feedstock for numerous industrial chemical processes. Most of the remainder is used to smelt steel and aluminum. China now produces half the world’s fluorspar; Mexico and South Africa are also important sources.

Because of its strongly bound fluorine and calcium ions, the fluorite in our mineral collections is quite safe and stable. But never heat fluorite or treat it with acid or any other chemical. As the fluorine martyrs so tragically learned, there is much more to fluorite than meets the eye.

This rock science column about fluorite minerals previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Steve Voynick.

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Quartz has long been the cornerstone of the gem and lapidary industry, especially as druzy gemstones. It is also popular in the collecting hobby. We would be hard-pressed to find many people who don’t have some variety of it in their collections.

Knowing how to identify quartz is important. This mineral has a relatively simple chemical structure. It is made of an atom of silicon (one of Earth’s most common elements) and two of oxygen (its most common element). Together, they form molecules that take the shape of a tetrahedron, rather like a pyramid with one corner pulled out to distort the whole. These, in turn, attach in a spiral fashion, forming beautiful hexagonal crystals that usually have pyramidal, or pointed, terminations.

Quartz Formation

If the quartz approaches pure silicon dioxide, it is clear and colorless, with air bubbles and miscellaneous impurities accounting for the milky hue often seen in quartz. Types of inclusions in quartz — other metal ions such as iron or aluminum — can become part of the internal arrangement, giving the potential for color.

When atoms combine to form molecules, they usually do so by sharing electrons, bonding them together. If everything balances electrically, the atom is stable and neutral. But when aluminum is present in quartz, it replaces some of the silicon atoms, and they differ in their electron balance. Silicon shares four of its electrons with two oxygen atoms in rock crystal. Aluminum, taking the place of silicon, has only three electrons it can share with two oxygen atoms. This electron difference makes the quartz susceptible to outside energies. Introduce a bit of radioactivity, and the quartz containing aluminum becomes a smoky color — one of the most popular varieties of quartz. We can make smoky quartz by bombarding clear quartz with radiation, something often done with Arkansas quartz.

Iron is another metallic element that can get into the atomic structure of quartz and affect the color. Iron is unusual because it can have four electrons to share, like silicon, or it can have only two or three, like aluminum. If it shares three electrons, the quartz can take on a yellow color. We call that citrine. If the iron has four electrons to share due to an unusual case of radiation, it will take on an amethyst (purple) color. We can change amethyst to citrine by heat-treating the quartz to disturb the electron arrangement.

The final color we see in crystallized quartz — the least common of the group — is rose. Various research has shown that the reason for the lovely, limpid pink color may have to do with the presence of titanium. Additionally, the Gemological Institute of America reports, “Research has shown that rose quartz owes its delicate pink color to microscopic inclusions of aligned silicate mineral fibers.” Again, the interaction of electrons produces the color emissions we see.

As you know, there are other colors of crystallized quartzes: green and blue, among others. These colors are largely due to inclusions, though citrine and amethyst quartz, as I mentioned, can be changed to green by heat-treating the stone.

Family Structure

The other quartz family of minerals falls under the heading cryptocrystalline quartz, a name that simply means it forms in crystals too small to see without magnification. That definition is a bit of an oversimplification, given that the submicroscopic crystals are fiber-like in most cases.

This variety’s main form is chalcedony, followed by agate, jasper, carnelian, sard, heliotrope, and onyx, among others. Within this grouping, there is a division. The agates are fibrous in structure, while jasper and flint are grainy quartzes.

Chalcedony is a particularly appealing gem material, as it is hard and easy to work and can come in a rainbow of colors, depending on impurities. The forms of iron in chalcedony color it red, yellow, orange, or brown. Copper minerals impart a blue shade, while nickel makes it green. Its formation mode can produce lovely alternating layers of colors that can be wildly patterned in bands, swirls, dots, and eyes. It is this multicolored, patterned chalcedony that is most popular with the lapidary.

Agates’ Quartz Foundation

The history of agate as a gemstone is longer than almost any other gem. It was gathered from streams in ancient times and used for jewelry. By the time the Romans controlled the world, the first great agate beds were being exploited around Idar and Oberstein, Germany. A huge agate gem business evolved there, outlasting the Roman and succeeding empires until the local supply dried up. At that point, German emigrants went searching for new supplies, and the great agate fields of South America opened.

For the most part, the Brazilian agate fields produce gems that lack bright colors. But agate is porous enough to be treated with heat or dyes to produce lovely, banded material; since each layer of chalcedony agate varies slightly in porosity, the dyes are selectively absorbed.

In the 1940s, one of the great sources of agates, naturally colored in a riot of hues, was opened up in northern Mexico. This material ranks as some of the better agate ever found. The source was volcanic formations, primarily in the state of Chihuahua. The agates here are so beautiful that they require special attention in an article such as this. The only problem today is availability.

Seventy years ago, Mexican fortification agates were readily available and possible to collect for the adventuresome. By 2001, the large beds of Mexican agate were nearly played out or closed to collecting. Where agates may still be found, they must be hard-won from the enclosing volcanic rock and can be hunted only with permission.

There are several agate beds in Mexico. The agates are often named for the source of locality, with Laguna, Coyamito, Gallego, Sueco, Apache, and Apache Flame agates among the best known. There are countless other sources of agate in Mexico, but these areas are the most notable. Gem material from each of these areas is distinctively colored and stunning.

What I like most about Mexican agates are the internal patterns they contain. Each stone is unique. Some are strictly fortification agates, with a series of concentric bands of varying width and color, yet with a pattern uniformity. Others have concentric rings of color with a point in the center, which is why this variety of agate is called “eye agates.” These eyes develop when internal, stalactitic growths in the agate are cut across the grain. If cut along their vertical axes, the pattern consists of two parallel bands of matching colors, slowly tapering to a rounded point. Some of the eyes have a small, hollow tube in the center where solutions may have entered or where some slender, needle-like crystal, now gone, gave rise to the stalactite form.

Scattered within many agates are color dots and streaks. Some are large enough to be seen with the unaided eye. Most are best seen under 10x magnification as bright dots or spots or colors that give the band’s overall color shade. These small concentrations of color have been shown to be largely iron compounds, with some manganese compounds as a second color source. In a few cases, snow-white dots are seen, which are usually bits of colorless quartz.

The fascinating feature of many agates is the “escape tube.” This is a bulbous shape that starts within the banding and extends toward and sometimes to the agate’s rim. These tubes are sometimes narrow in the center with a bulging tip. If they touch the rim of the agate, they spread out in a funnel-like form.

For a long time, these escape tubes were thought to be the avenue through which the silica solutions entered the hollow geode or gas pocket in lava. These solutions were credited with creating the banding for which these agates are prized. However, modern studies have shown that the reverse is actually true.

The elongated structures actually are escape tubes. As the agate formed from a silica gel material, increasing pressure caused the remaining solutions to probe and penetrate the agate layers that had already formed at their weakest point. This movement to reach the rim of the agate so as to relieve the building pressure caused the existing, fresh layers to be dragged toward the flow of the escape. So, when you look carefully at an agate with an escape tube, you can readily see the distorting effect this movement has created. The regular fortification pattern is pulled like taffy into unusual and irregular forms. All of this adds to the internal beauty of that agate. Couple that with a nice quartz crystal lining in the center of the agate and you have something quite attractive.

One of the most beautiful quartz forms used in jewelry is quite valuable, even though the quartz is an ordinary milky white. Of course, the fact that it has stringers and veins of gold running through it may account for its higher-than-usual value. Called “gold in quartz,” this lovely material is contrasting snow-white and rich, buttery yellow. It can be slabbed and polished, then used as cabochons, for beads, or as an inlay gem material, among other uses. Set in rings and brooches, it is an instant conversation piece, and when used to make jewelry boxes and ornamental objects of art, it is quite elegant. Much of the “gold in quartz” comes from California’s mines, though it may be expected any place gold occurs in white quartz veins.

As long as people collect gems and minerals, there is going to be an attraction to quartz. Many collect only that singular species, which is understandable, given that there are myriad sources the world over. It comes in a great variety of wonderfully showy crystallized forms and in several attractive colors. The massive varieties can be riotously colored and patterned agates or richly colored solid gems suitable for jewelry making. No wonder quartz is and always will be one of the most popular minerals.

This story about the quartz mineral group previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Bob Jones.

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