tiger's eye | Rock & Gem Magazine https://www.rockngem.com Rock & Gem Magazine Mon, 27 Nov 2023 14:37:30 +0000 en-US hourly 1 https://wordpress.org/?v=6.3.2 https://www.rockngem.com/wp-content/uploads/2018/10/cropped-Favicon-32x32.jpg tiger's eye | Rock & Gem Magazine https://www.rockngem.com 32 32 What Gives Minerals Color? https://www.rockngem.com/phenomenal-mineral-colors/ Mon, 27 Nov 2023 11:00:39 +0000 https://www.rockngem.com/?p=9637 What gives minerals color? It’s an important question because mineral color is a primary way to identify minerals and assess their value. Mineral color can have several different causes including impurities and their chemical elements. But a host of minerals get their color from their internal structure, called a physical phenomenon, that affects the way […]

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What gives minerals color? It’s an important question because mineral color is a primary way to identify minerals and assess their value. Mineral color can have several different causes including impurities and their chemical elements. But a host of minerals get their color from their internal structure, called a physical phenomenon, that affects the way light is reflected to the viewer.

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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.

Diffraction caused by perfectly aligned tiny spherules of silica split light into its lovely colors in precious opal. (Bob Jones)

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.

This arsenopyrite on quartz from China has a colorful, iridescent coating its normally silvery crystals. (Photo by Bob Jones)

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.

The asterism in the Delong star ruby is caused by included fibrous crystals of the mineral rutile, which reflect light in a six-rayed star pattern. (Natural History Museum collection)
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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

The phenomenon of aventurescence is named for aventurine quartz, in which tiny, green flakes of included chrome mica are scattered throughout the quartz. (Photo by Jim Brace-Thompson0

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.

Under incandescent light the same specimen of alexandrite crystals shows hues of red and yellow. (MICHAEL LEYBOV/FERSMANN MUSEUM SPECIMEN)

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.

A group of alexandrite crystals presents as a fine green color under sunlight. (MICHAEL LEYBOV/FERSMANN MUSEUM SPECIMEN)

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.

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Types of Gemstones By Letter (S-Z) https://www.rockngem.com/meet-gemstones-by-letter/ Tue, 21 Nov 2023 11:00:44 +0000 https://www.rockngem.com/?p=18086 Types of gemstones like sapphires and tiger’s eye are well-known and zircon has been around for two millennia, however, it’s more difficult to find stones such as vesuvianite with its origin in Mount Vesuvius. Here we’ll explore gemstones that start with the letters S to Z. Even for gemstones that are not as popular, learning […]

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Types of gemstones like sapphires and tiger’s eye are well-known and zircon has been around for two millennia, however, it’s more difficult to find stones such as vesuvianite with its origin in Mount Vesuvius. Here we’ll explore gemstones that start with the letters S to Z. Even for gemstones that are not as popular, learning the details of their origination and modern uses inspires us to look closer at them. This is the third in a three-part series covering types of gemstones by letter starting with the letters A to I and gemstones that begin with the letters J to R.

Sapphire

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One of the official state gemstones of Montana, sapphires hold a special place in the Treasure State where they are readily found. Sapphires and rubies are both corundum, an aluminum oxide mineral typically found in crystalline form. The only difference between the two is the presence of chromium. If the corundum is red, it’s ruby. Otherwise, it’s always a sapphire.

One of the most desired types of gemstones, the most well-known sapphire hue is deep blue, but these gemstones are found in pink, green, violet, orange, purple and even brown. When they’re not blue, they’re referred to as fancy sapphires. These colors are because of the varying degrees of chromium, titanium oxide and iron within the stones. Sapphires also possess a trait called asterism where needle-like inclusions create the appearance of a six or twelve-patterned star. Beyond this unique characteristic appreciated by faceters, sapphires have a Mohs Amy Grisak; Getty Images/Science Photo Library value of nine, just below a diamond, making them extremely durable and an excellent choice for jewelry.

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Tigers Eye (Getty Images/Dorling Kindersley: Richard Leeney)

Tiger’s Eye

This distinct gem has a long history of fending off the “evil eye,” with its resemblance to a cat’s eye. In gemology, this trait is called chatoyancy, a French term meaning “shining like a cat’s eye.” When there are crocidolite (blue asbestos) fibers within cabochon-cut gemstones running parallel to each other, the rounded surface allows the light to reflect in a way that gives the tiger’s eye its signature look. Originally, scientists thought this phenomenon occurred when the crocidolite within the stone was changed by iron oxide and replaced with silica. But even though the coloration comes from this process, some researchers believe it’s actually crocidolite inclusions within columns of quartz within the stone that form the distinct paralleling nature.

Regardless of how it formed, tiger’s eye is a favorite gem for tumbling and with a Mohs value of seven, it’s a versatile stone for a multitude of uses. While it’s a ubiquitous stone these days, in the 1870s a single carat of tiger’s eye was worth an ounce of gold.

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Unakite (Getty Images/Dorling Kindersley: Richard Leeney)

Unakite

Unakite is a terrific example of when a gemstone is a true rock as this beautiful pink and green specimen is a composite of metamorphic rocks including orthoclase, epidote and milky quartz. It’s formed during hydrothermal metamorphosis when the epidote replaces the silicate minerals, primarily plagioclase, within the granite. The epidote is green within unakite, while the pink orthoclase feldspar and quartz create the colorful speckling.

First found in the Unakas Mountains of Western North Carolina and Eastern Tennessee, it’s sometimes found in the rivers of the region, along with the beaches of Lake Superior where glaciers deposited the metamorphic rocks. With a Mohs rating of six to seven, unakite is among the types of gemstones that tumble well. It has been used to make small sculptures or is cut for jewelry. As eye-catching as it is, unakite is also valuable in construction on many levels, including being used as trim along the front steps of the south entrance of the Smithsonian National Museum of Natural History. It is also sometimes used less visibly as crushed stone in highway construction.

Vesuvianite

Sometimes called idocrase, vesuvianite was originally found along Mount Vesuvius in Italy, which buried the nearby inhabitants of the city of Vesuvius on August 24 in 79 AD, ironically during the festival of Vulcanalia, the god of fire. In the world of gem cutting, vesuvianite often refers to the rough stone, while the faceted gems are called idocrase.

Regardless of the name, this is a calcium-aluminum-silicate mineral that forms in a tetragonal structure. Its most popular colorations range from yellowish green to brownish or olive green, although there is a blue version called cyprine that derives its color from trace amounts of copper. With a Mohs value of six, vesuvianite isn’t a very hard stone and is often used for larger jewelry and sculptures. In its green coloration, it’s sometimes mistaken for other types of gemstones like peridot, although vesuvianite is far rarer.

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White Topaz (Getty Images/Jeny S)

White Topaz

While topaz is found in practically the entire color range, the white topaz is the clear version and boasts a similar appearance to a diamond. Outside of cost, there are distinct differences between the two types of gemstones. Topazes and diamonds are closely alike in clarity and color, but brilliance is where diamonds shine. Hardness is another determining factor. Diamonds reign supreme rating at Mohs 10, while topazes register as a Mohs eight, considerably less durable with a greater risk of scratching.

Topaz is created when water and magma react during the metamorphic process creating pegmatite featuring natural topaz that is typically initially clear. While the wide variety of colors is because of impurities, such as chromium replacing the aluminum within the stone, white topaz is the gem in its purest form. Specific hues are also created with heat, irradiation or the application of metal oxides to enhance colors. Topaz also exhibits pleochroism where the gem exhibits different colors depending on its angle, although the white topaz tends to remain consistent in its coloration.

Xenotime

On occasion, there are types of gemstones cut from this rare earth mineral, often found in yellowish-orange to reddish-brown hues, although high enough quality stones to facet are rare.

Like topaz, xenotime is found in pegmatite formations, as well as igneous rock and gneiss. Uranium and thorium are often found within this stone, creating natural radioactivity, although it is more commonly seen as a source for the transition metal yttrium, which is used as an alloy in the production of camera lenses and lasers. Its name is derived from the Greek terms for “vain” and “honor” in an early scientist’s snarky rebuke of another. Initially, Swedish chemist Jöns Jacob Berzelius believed he discovered a new element within the xenotime. This turned out to be the already known yttrium, which prompted mineralogist François Sulpice Beudant to throw down a bit of shade on the claim.

Yellow Kunzite

True gemologists might shudder at the inclusion of yellow kunzite in this types of gemstones list, but it’s an example of when marketing can be misguided. As a rule, kunzite is a pink to light purple variety of spodumene, a lithium-rich mineral found, once again, in pegmatite formations. Manganese gives kunzite those attractive colors. When the gem is yellow, it’s typically just called yellow spodumene. The name change might be a matter of one word sounding more appealing than the other, but it is still misleading as kunzite implies a specific hue. With a Mohs value of six and a half to seven, it is not a very durable gemstone, but it’s possible to find specimens of 20 carats or more. Spodumene, in general, is an important source of lithium, which is critical for car batteries, phones and medicine. It is mined in Afghanistan, Pakistan, California, North Carolina and South Dakota.

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Zircon (Getty Images/imagenavi)

Zircon

Not to be confused with the synthetic cubic zirconia, zircon earned its place as a popular gemstone 2000 years ago. Found in sand and as part of many of the rocks throughout the world, zircon is one of the oldest minerals on earth. Because of its uranium content, scientists in Australia dated it back 4.4 million years. Not all zircons are radioactive, but those that are can be heat-treated to stabilize the integrity of the stone by slowing the degradation of the crystalline structure. In their natural form, zircons are found in colors ranging from clear to yellow, green, purple, brown and grays, which are typically caused because of radiation or impurities. Blue zircons, which have been popular since Victorian times, are created through heat treatments.

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

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9 Types of Inclusions in Quartz https://www.rockngem.com/9-types-of-inclusions-in-quartz/ Mon, 15 May 2023 10:00:30 +0000 https://www.rockngem.com/?p=20402 Different types of inclusions in quartz can create beautiful and unique gemstones! Quartz inclusions take one of the most common minerals on Earth to a new level of science and beauty. Think quartz is common? Think again! As mineralogist John Sinkankas observed, “One could devote an entire lifetime to collecting examples of inclusions occurring only […]

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Different types of inclusions in quartz can create beautiful and unique gemstones! Quartz inclusions take one of the most common minerals on Earth to a new level of science and beauty. Think quartz is common? Think again! As mineralogist John Sinkankas observed, “One could devote an entire lifetime to collecting examples of inclusions occurring only in quartz!”

What is an Inclusion?

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At its most basic, an inclusion is a material that was trapped inside a mineral as it formed. Quartz is referred to as a host if it contains other minerals within itself. These other minerals, in turn, are referred to as inclusions. Inclusions can look like locks of golden hair, fuzzy moss or even floating spheres.

With precious gemstones, inclusions are an indicator of a natural versus a synthetic stone. Completely flawless stones are rare in nature, so a lack of imperfection screams synthetic and often lowers the value. But with quartz, when you add the imperfection of inclusions, the value can jump exponentially. An ordinary quartz crystal with dings can fetch as much as $200 if it has even a small inclusion of sky-blue ajoite. Google “tourmaline in quartz” and the price might be $150, even if the quartz crystal is hohum and the tourmaline is common black schorl.

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Here, you can see how rutile grew first on the wall of a cavity, only to be enveloped later by a quartz crystal.

What is Quartz?

Quartz is silicon dioxide (SiO2). You find it as crystals, masses, agates and jaspers, opals and other staples forming the basic diet of most lapidary artists.

Perfectly formed crystals are called euhedral, with eu meaning “good” or “ideal.”

A euhedral crystal is one that is bounded by regular, well-developed faces. With quartz, there are six faces, making it a hexagonal crystal. Pure quartz, often referred to as rock crystal, is colorless and transparent. It looks much like ice. Indeed, ancient Greeks believed it to be ice that never melts because gods crafted it deep within Earth. The Greek word krystallos means “ice.”

Quartz often is divided into crystalline, or large visible crystals, and cryptocrystalline, which includes agate and jasper with fibrous aggregates of microscopic crystals. This article focuses on larger, crystalline varieties of quartz.

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Inclusions like chlorite can look like moss or plants.

Types Inclusions in Quartz

Quartz crystals forming in vugs or cavities (as opposed to solidifying out of magma) often begin under high temperatures and pressures as molecules in a solution that is aqueous, or water-based. Within the solution, silica atoms attract one another because of chemical and electrical forces.

They interlock and grow in repeating crystal patterns dictated by the chemistry of the constituent elements. As they grow, the surrounding solution can change. Thus, the crystal might stop growing for a time, then start growing again. In between, other elements might get introduced and form other minerals that get incorporated into the quartz crystal. All sorts of things might happen depending on the atomic and mineral nourishment received from the ever-changing solution.

Inclusions may form before, after, or at the same time as the host crystal. They may consist of other minerals, light dustings or druses, gases or fluids, or natural fissures and cracks.

Protogenetic Inclusions

A protogenetic inclusion happens when a mineral inclusion grows first and a quartz crystal grows around it. Often, quartz is one of the last minerals to solidify out of a solution. Thus, a mineral-like rutile might form on a cavity wall and later be enveloped by quartz, forming so-called sagenitic sprays.

There are specimens where the quartz crystal stopped growing and rutile needles project out of the quartz crystal face.

Syngenetic Inclusions

Inclusions formed at the same time that the host was growing are called syngenetic inclusions. At times, a quartz crystal pauses in its growth and a mineral settles on the crystal face only to get incorporated inside the quartz if it begins to grow again. When this happens, you see what’s called a phantom inside the quartz crystal or you may see what appears to be perfectly formed crystals of minerals like fluorite or garnet “floating” inside the quartz.

Rather than floating, they have adhered to a previous growth phase of the quartz crystal before it continued its growth.

Gazing into a phantom crystal, you literally see the past in the ghostly form of the crystal’s former shapes. In addition to larger crystals, you might see tiny bubbles or mineral grains coating earlier crystal faces that stopped growing. When they started growing again, the coatings became trapped in a thin layer. Sometimes, this happens over and over again, faithfully marking the crystal’s growth zones much like growth rings recorded in trees.

Epigenetic Inclusions

Some inclusions form after a quartz crystal completes its growth. This might include fractures or other internal damage due to natural processes like heat, pressure or radioactivity. Or it might include so-called alteration products (a mineral that changed because of heat and pressure).

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Iron oxide inclusions may appear as discrete red dots coating a phantom or may color an entire quartz crystal.

Common Types of Inclusions in Quartz Often Encountered

Entire collections have been made of the varied inclusions within quartz crystals. The following are common examples that can easily be collected in the field or at gem shows.

Rutilated (Sagenitic) Quartz

Rutilated or sagenitic quartz contains gold-colored rutile inclusions. Sometimes these are in delicate fanned patterns like sprays of blonde hair or feathers. Other times, they are acicular (needle-like) clusters. These have been called hairstones, Venus’ hair, Cupid’s darts, or fleches d’amour (“arrows of love”). Sometimes the rutile needles radiate out in starburst fashion from a cluster of hematite crystals. This is called “star rutile.” Rutilated quartz most commonly comes from Bahia, Brazil.

Tourmalinated Quartz or Tourmaline Quartz

Tourmalinated quartz contains long, thin tourmaline crystals. Often, these are common black schorl but they also may be more precious pink or green elbaite. These are found in pegmatite deposits worldwide, including the Pala region of southern California.

Chlorite, Actinolite, and Amphibole Phantoms

The minerals chlorite, actinolite, and amphibole can leave green to black dustings on phantom faces within a quartz crystal. But sometimes they form dramatic fuzzy clumps that look for all the world like moss or plants. Quartz crystals with such inclusions are highly prized and sought.

Iron Oxides

Iron oxides like hematite can grow as small red dots or plates that might be visible as dustings on a phantom crystal face. If there is an especially large abundance of hematite plates, the whole crystal may have a bloodred cast and you need a loop to see the platelets within.

Larger Mineral Crystals

Many nicely formed crystals of other minerals are sometimes seen floating within a quartz crystal. Most often, they aren’t really floating. Rather, they have adhered to a phantom crystal face. You commonly see such crystals as pyrite, fluorite or garnet.

Fluid and Gas Inclusions

Fun specimens are quartz crystals where the dealer has circled an area with a Sharpie marker. This is done to help buyers see inclusions of liquids and bubbles that rock back and forth in tiny cavities within the quartz.

Such inclusions can be used to determine the heat and pressure at which the original crystal formed. Scientists determine this by heating a quartz crystal until the bubble or fluid exsolves or disappears.

Some quartz crystals are completely filled with gas and liquid inclusions trapped as veils and wisps within minute cavities. They make the entire crystal white and opaque. Such crystals are popularly known as milky quartz.

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Inclusions of slender crystals tightly packed can result in chatoyancy, as in this tiger eye from South Africa.

Inclusions in Quartz Causing Interesting Optical Effects

Other inclusions create almost magical optical effects because of the way they are aligned within the quartz host.

Chatoyancy, or Cat’s Eye

Chatoyancy is an optical effect created by tiny tubes or slender crystal inclusions lined up and packed tightly in a row within a host mineral. Jiggle the stone back and forth under bright light and a shining streak running at a right angle to the inclusions can be seen, particularly when the stone is cabbed or otherwise rounded. It looks much like the slitted pupil of a cat’s eye.

This effect is strong with tiger’s eye quartz from South Africa. The inclusion, in this case, starts out as crocidolite, a variety of fibrous asbestos. Quartz grows over the crocidolite and is dissolved and replaced in a process that results in a pseudomorph. The crocidolite is entirely replaced by the quartz, but its finely fibrous structure remains along with a staining of iron minerals, giving the quartz a silky golden sheen with fine chatoyancy.

Asterism or Star Stones

Asterism is an optical effect showing two or three crossed lines that look like stars with four or six rays radiating out from the center. Star stones occur when extremely fine microscopic needle-like inclusions of minerals like rutile orient themselves to the internal six-sided crystal structure of quartz during a process called exsolution.

The inclusions are so fine they are normally invisible to the eye. It is these inclusions that reflect light, showing a shimmering star. This effect can be seen when the stone is cut as a cabochon or rounded as a sphere.

Deposits giving rise to star rose quartz have been found in India, Sri Lanka, Brazil, the Ontario province of Canada and California’s Greenhorn Mountains.

Aventurescence

Aligned inclusions can produce an optical effect known as aventurescence. Small green fuchsite (“chrome mica”) plates line up in mutual orientation as quartz forms and incorporate them. This usually happens with massive deposits of quartz as opposed to discrete crystals. The result, when cabbed, looks like a stone containing sparkling metallic confetti. Green-spangled aventurine quartz is common in the area of Madras, India.

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Inclusions like chlorite can look like moss or plants.

Included Quartz as a Lapidary Stone

While inclusion in any sort of gemstone material is often considered an undesirable flaw, when clear and inexpensive quartz is used for faceting, cabbing, or carving, an inclusion is viewed as an enhancement.

Rutilated quartz, in particular, is considered desirable. If a quartz crystal hosting inclusions is broken or otherwise not very aesthetic as a crystal specimen, it can serve as a prime candidate for a wonderful piece of jewelry, whether cabbed or faceted.

Precious metals like gold or silver might be included, as from the Sixteen to One Mine in California. These, too, make for wonderful— and valuable—cabochons for mounting into rings, brooches or other jewelry.

Think quartz is common? Think again!

How wonderful it is to be included!

This story about inclusions in quartz previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Jim Brace-Thompson. 

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What Are Lucky Stones? https://www.rockngem.com/what-are-lucky-stones/ Mon, 13 Mar 2023 10:00:33 +0000 https://www.rockngem.com/?p=19567 What are lucky stones? The list of traditional good luck charms is as long and diverse as the list of people who carry them. Think rabbit’s feet, lucky pennies and horseshoes hanging above a door. The stories of people relying on good luck charms or talismans go back centuries, but you don’t need to look […]

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What are lucky stones? The list of traditional good luck charms is as long and diverse as the list of people who carry them. Think rabbit’s feet, lucky pennies and horseshoes hanging above a door. The stories of people relying on good luck charms or talismans go back centuries, but you don’t need to look that far. There’s a tennis player with a lucky shirt, another with lucky shower sandals, and a basketball player with lucky shorts. Don’t have a good luck charm yet? No problem. If you like rocks, you’re in the right spot. Many are believed to bring good luck. What are lucky stones? Here’s a look at some of those good luck rocks and how to prepare and use them.

What is Luck?

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You’re invited to a party. There are a lot of people there you don’t know and you strike up a conversation with one of them. This person asks you about your work and you share with them the idea you have for the business you want to start. It turns out this random person is a wealthy random person; a wealthy person who is now interested in investing in your business. Is that luck?

Some would argue that luck has nothing to do with it. They argue the investor is interested because you have a good idea and know how to present it. Others will argue that it was lucky that you spoke with someone with money to invest. After all, you could have just as easily spoken with someone who wants to borrow money. It’s impossible to prove either viewpoint. For now, we are going to assume luck does exist but sometimes it might need a helping hand.

Different Stones for Different Kinds of Luck

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Tumbled stones. Photo courtesy of Rochas Brasil Pedras Decorativas

Different types of stones are believed to bring luck in different areas of life. Perhaps you are seeking good luck in a financial venture. Maybe you’re planning a trip and want good luck with safe travel. Perhaps you’re starting a new relationship and you want to be lucky in love. Or maybe you’ve been lucky in love and now you want to start a family.

The type of luck you seek will dictate the stone best suited to assist you. There may also be times when using more than one type of stone will be beneficial and increase your chances.

First, let’s look at five stones believed to bring good luck. Then we’ll look at a few ways to use more than one type of rock so you can dial in the luck you seek.

1. Amazonite

Some refer to amazonite as the “gambler’s stone” because of a belief in the stone’s ability to bring good luck in games of chance or when starting a new venture.

2. Citrine

Known as a stone of abundance, manifestation, and good luck, citrine is believed to promote good fortune and prosperity. When used as an aid in manifesting your desires, it can help with your creativity, love life, vitality, or fertility.

3. Jade

In addition to attracting abundance and prosperity, jade is believed by some to help strengthen your health and increase longevity. Many view jade as one of the most powerful of all the good luck stones.

4. Tiger’s Eye

This stone is reputed to bring good luck in matters of wealth and money. Tiger’s eye is also viewed as a stone of protection.

5. Peridot

Many believe peridot will attract financial well-being and refer to it as the “money stone.”

Many other stones such as rose quartz, garnet, and labradorite are also believed to bring good luck. Which rock is best for you? Like many questions related to metaphysics, there isn’t a single correct answer. The best approach is to combine what you know about the qualities of a stone with your intuition and proceed from there.

what-are-lucky-stones
Good luck stones can be worn as jewelry. Photo courtesy of Katerin Buinistky

Which Stone(s) to Use and How

Determining which stone is right in which circumstance requires looking at the full spectrum of the stones’ metaphysical properties. You may discover that rather than using one stone, it would be better to use two or more stones that have complementary properties.

For example, a tiger’s eye is used both for good luck and for protection. If you anticipate a situation involving a verbal conflict, you may want to pair a stone such as turquoise that improves communication with your lucky tiger’s eye. If you’re at the start of a new romantic relationship, you might want to pair rose quartz (for love) with jade or amazonite. If you’re already in a relationship and hope to add children, then a good luck stone coupled with a stone such as citrine that brings fertility might be in order.

When you are hoping to land a new client for your workplace, you might combine malachite’s strong financial connection with citrine’s luck in manifesting. Like most of the metaphysical aspects of stones, there is a wide variety of ways to use the stones, and no one is the right way.

The best way to use your lucky stone depends on the situation. Let’s look at rose quartz again. Rose quartz is believed to be connected to the heart chakra. If you seek luck in love, a pendant or pin containing rose quartz and jade worn near your heart chakra might work best for you. If you have a business, placing a jade or citrine stone in your cash drawer could help to boost your cash inflow.

Stones and Feng Shui

Stones often play a pivotal role in Feng Shui. In Feng Shui, certain areas of your home are believed to be energetically connected to specific areas in your life such as relationships, career, knowledge, and prosperity. Placing a good luck stone in one of these areas may help to improve that area of your life.

To locate where these areas are in your home, a Feng Shui practitioner uses a tool called a bagua. The Bagua is a kind of map that helps to pinpoint these energy centers in your home. Placing a good luck stone in the prosperity section may ofing about an influx in money. If there is trouble in your relationship, placing a good luck stone in that area may help improve the relationship.

It’s important to note that improving a situation may be, and often is, more complicated than simply placing a stone. If you’re looking to use Feng Shui to improve an aspect of your life, a Feng Shui practitioner can help you identify the best stones to use and where to place them.

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Setting your intention. Photo Courtesy of Kira auf der Heide

How to Prepare the Stone for Use

Once you know which stone or stones you want to use, you need to clean and prepare them. Remember stones are believed to hold energy. Therefore, when you first get a stone it’s important to cleanse the stone to clear any old energy it may hold and start fresh.

Before you begin any cleansing technique, research the stones you are using. You must know how to properly handle the rocks to avoid damage. For example, using water to clean a friable rock may cause serious and irreparable damage. Instead of using water, this type of rock can be cleaned by putting it in the dry sea or rock salt—no water—for several hours. When you’re done, be sure to thoroughly remove all traces of the salt. A stone that is not friable can be rinsed under running water or immersed in saltwater.

Many people will also smudge their rocks. Smudging is the process of passing the stone through the light of a candle or smudge stick. Setting the stone in the moonlight, especially during a full moon, is another popular method of cleansing.

Some stones, like carnelian, can be used to cleanse other stones. You can place a piece of tumbled carnelian in with other tumbled stones or crystals. The natural vibration of the carnelian will work to cleanse and energize the other stones. NOTE -To avoid scratches and damage, this should only be done if all the stones are tumbled.

As you begin the cleansing process, you need to set your intention. When setting an intention, it’s important to be specific about what you want. Hold the rock in your hands and your mind hold the intention that all negativity be removed. Concentrate on how you want the rock to help you. You can say something like “It is my intention for this stone to hold only positive energy and to bring me financial abundance.” Intentions are personal, say words that resonate with you. Decide what feels and sounds right to you and go with it.

You never know, with the right stones and the right intentions, good luck may come your way!

This story about what are lucky stones appeared in Rock & Gem magazine. Click here to subscribe! Story by Kris McElhinney.

The post What Are Lucky Stones? first appeared on Rock & Gem Magazine.

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Top 10 List of Metaphysical Rocks https://www.rockngem.com/top-10-list-of-metaphysical-rocks/ Mon, 04 Jul 2022 10:00:34 +0000 https://www.rockngem.com/?p=16236 Metaphysical rocks are a personal choice, but the more people you ask, the longer the list of common rocks that many people choose. The following is an alphabetical listing of 10 stones that are most preferred along with their properties and uses. It’s important to remember there is no finite or definitive list of the […]

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Metaphysical rocks are a personal choice, but the more people you ask, the longer the list of common rocks that many people choose. The following is an alphabetical listing of 10 stones that are most preferred along with their properties and uses. It’s important to remember there is no finite or definitive list of the metaphysical uses of rocks and crystals. You may feel drawn to a particular stone or find that it affects you differently than it does someone else.

1. AMETHYST

Known for helping to develop a person’s spiritual connection and abilities, amethyst is often used in meditation. Purple is the color associated with the seventh or Crown Chakra. It is the February birthstone.

2. APACHE TEAR

These are small round pebble-like pieces of obsidian, each containing flecks of white. Apache Tears are often used to help release grief.

3. BLACK TOURMALINE

Tourmaline comes in several different colors. The black is used for protection against negative energy.

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4. CITRINE

Citrine restores warmth and energy. Like the tiger’s eye, citrine can be used to increase your personal power and is associated with the third or Solar Plexus Chakra. It is the November birthstone.

5. HEMATITE

Hematite helps improve focus and provides clarity when your mind begins to spin out of control. Some associate it with the first or Root Chakra.

6. MALACHITE

Malachite helps in attaining goals and has a strong financial connection. Often associated with the fourth or Heart Chakra.

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Malachite

7. RED CARNELIAN

Red Carnelian helps to increase creativity, passion and self-confidence. Can also be used to clean other stones and crystals. Both the ruby and red carnelian are seen as birthstones for July.

8. SHUNGITE

Similar in chemical composition to coal, shungite also contains the carbon molecule, Fullerene. Shungite has a wide range of uses from improving the health of bees to water purification to protection from the harmful effects of electric and magnetic fields (EMFs).

9. TIGER’S EYE

Tiger’s eye is often used in jewelry. It helps to ground the wearer and to remind them of their personal power. Tiger’s Eye is often associated with the third or Solar Plexus Chakra.

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Tiger’s Eye

10. TURQUOISE

Turquoise is believed to be a powerful stone, it too is often used in jewelry. It aids in repelling negativity and restoring harmony and joy. It is associated with the Heart, Throat and Third Eye Chakra. Some view it as the birthstone for Sagittarius.

This story about a top 10 metaphysical rocks list previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Kris McElhinney.

Disclaimer: The metaphysical properties discussed in this story 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.

The post Top 10 List of Metaphysical Rocks first appeared on Rock & Gem Magazine.

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