Custom Jewelry | Caring for Gemstones | Definitions & Glossary

DEFINING AND CLASSIFYING GEMSTONES

Crystal (C)

Is a general term for a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. Natural crystals include quartz, diamonds and emeralds. Glass crystals, such as Swarovski, are manmade and incorporate lead to produce a sparkling, crystalline appearance. Both natural and glass crystals come in a wide range of colors, shapes and sizes.

Cryptocrystalline (CC)

Is a rock texture which is so finely crystalline, that is, made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light.

Gemstones (G)

This term broadly applies to minerals that are highly prized for beauty, durability and rarity. A gemstone is usually enhanced in some manner by altering its shape, generally by cutting and polishing. Gemstones are regarded as precious or semi-precious, depending on their composition and rarity. Some rocks and even organic materials, such as coral and pearls, are also considered gemstones.

Metals (M)

Among the most popular precious metals are silver, gold and platinum. Some common base metals, which generally corrode more easily than precious metals, are copper, aluminum, nickel and steel.

Minerals (MI)

Naturally occurring solids whose chemical compounds are composed of two or more elements with a distinctive internal crystal structure.

Organic (O)

Produced from the earth or water, but not made of stone. Organic gemstones are generally a byproduct of living organisms; they are not as durable as gemstones composed of minerals.

Precious (P)

Ruby, emerald, sapphire and diamond gemstones are considered precious because of their rarity. Pearls, though organic, and opals are often considered in this category as well.

Quartz (Q)

A crystalline mineral that comes on many forms. Many semiprecious stones are from the quartz family; this common mineral is found worldwide.

Semiprecious (S)

More readily available than precious gemstones and more affordable.

Glossary of Stones

Amber (O, S)

An organic gem that comes from preserved tree resin. Its basic orange ranges from dark honey to reddish orange to hazy lemon. Although rarer, amber may vary in color from green to blue.

Amethyst (MI, S)

Is lilac to deep purple is the most highly valued of all the quartz varieties. In ancient times the amethyst was thought to have mystical and protective powers, particularly the ability to prevent intoxication; for this reason the stone’s name is derived from the Greek phrase amethystos, meaning ‘not drunk’. The deeper the color, the more valuable.

Ametrine

Is a variety of quartz that contains both amethyst and citrine sectors in the same crystal. Also known as trystine or by its trade name as bolivianite.

Aquamarine (MI, S)

The mineral beryl has been considered a gemstone since prehistoric times. Aquamarine is a transparent variety of beryl, having a delicate blue or turquoise color. It is closely related to the emerald.

Aventurine (CC, Q)

Is a member of the quartz family and comes in green, red/peach, blue, white and brown. Its name is derived from the Italian a ventura, a type of glass discovered around 1700 which resembles aventurine. This stone is great for creativity, motivation, growth and confidence.

Bamboo (O)

Is the fastest growing woody plant in the world. It is well regarded for its strength and diverse uses. Throughout Asia, Bamboo are economically and cultural significant. Its long life makes them a symbol of longevity, whereas in India it is a symbol of friendship.

Blue Lace Agate

Is a pale blue and white banded variety of Agate. Agate is actually a derivative of Chalcedony. It can be obtained in all sizes through the world. It is proclaimed to have qualities that balance yin and yang energy.

Bone (O)

Most bone beads today are made of ox or cow bone.

Brass (M)

Brass has been used throughout time as decoration for its bright gold-like appearance and its nearly tarnish-resistant properties. Back in the day, polished brass was often used as a mirror. Brass has likely been known to humans since prehistoric times. In the German village of Breinigerberg, an ancient Roman settlement was discovered where a calamine ore mine existed. Thus, brass was produced by melting copper together with calamine, a zinc ore.

Note: This image is actually 22k plated gold over brass.

Calcite (C)

Calcite has a variety of habits which makes it an especially interesting crystal. Scientist have discovered its optical properties such as double refraction of light, such that objects viewed through a clear piece of calcite appear doubled in all of their parts and producing wavelengths of extraordinary refractive indices. It is generally transparent to opaque and can be gray, yellow or green.

Carnelian (MI, S)

A semiprecious stone that is usually translucent blood red to reddish orange in color. It has been believed that it calms the temper, gives its owner courage and helps the timid to speak eloquently.

Chalcedony (CC, Q)

Is a variety of quartz that is usually pale blue or grey. It is generally uniform in tint but some varieties have multiple colored internal markings.

Chrysocolla (M)

A massive, amorphous copper mineral of blue to green color that is sometimes confused with Turquoise. The name comes from the Greek chrysos, “gold”, and kolla, “glue”, in allusion to the name of the material used to solder gold.

Chrysoprase (CC)

Highly coveted for its apple-green to deep green color, Chrysoprase is a gemstone variety of chalcedony. It is composed of crystals that remain undetectable under normal magnification. This gemstone is found throughout the world in Australia, Germany, Russia, Arizona, California and Brazil.

Citrine (MI, S)

Is less common than the amethyst. Yellow to yellow-brown in color and resembles the gem topaz. Good citrine crystals are surprisingly rare.

Coral (O)

Is a rare, organic gemstone which can no longer be gathered due to environmental restrictions. A renewable resource collected in the wild from a limited environment, it is the remains of a delicate and beautiful living organism that flourished deep beneath the waves. Found primarily in Asia, Africa and Mesoamerican. Ancient societies believed in that coral was a protective charm that brought good fortune and protected people from harm.

NOTE: StyleFolioJewelry.com’s coral pieces were made before the extraction of coral was prohibited.

Crystal (C)

Druzy (CC, M)

Druzy is formed when water carrying dissolved silicia is forced into a rock cavity and quickly cools. The tiny crystals that from form this are called Druzy.

Dumortierite (M)

This mineral may be blue, violet, pink or brown. If it contains a streak it will be white. It is transparent to translucent. It is attributed to helping one to speak his/her mind.

Emerald (MI, P)

This rare and valuable precious stone comes in shades of green to blue-green. The more saturated the color, generally the higher the price. Synthetic emeralds, developed in the 1930’s, have fewer imperfections and are difficult to distinguish from natural.

Fluorite (C)

Fluorite can be clear, blue, green, purple, yellow, pink, red, black and brown in color. Often multiple colors can appear in the same speciman.

Garnet (M)

Traditionally red in color, garnet is part of a group of minerals that includes six main varieties. The chemical composition of garnet influences its many colors and shades.

Howlite (MI)

Howlite is always an opaque white or gray color with black web-like veins or streaks. It is often dyed and can be easily confused with Turquoise.

Iolite (MI)

The name “iolite” comes from the Greek word for violet. Gem quality Iolite varies in color from sapphire blue to blue violet to yellowish gray to light blue as the light angle changes.

Jade (MI)

Jade defines two minerals, nephrite and jadeite, of similar appearance but different chemical composition. Both minerals are found in a wide range of shades of green, brown, yellow, grey and pink and may be either translucent or opaque. They may be milky or cloudy in appearance and sometimes speckled with tiny black spots.

Jasper (MI, CC)

Is an opaque mineral from the quartz family with a smooth surface that can be highly polished. When the colors are in stripes or bands, it is called striped or banded jasper. Jasper can appear as an opaque rock with shades of red due to mineral impurities. Jasper is also brown, yellow, green, blue and purple.

Jet (G, O)

Jet is a minor gemstone and is dervied from high pressure wood decomposition.

Kunzite (M)

Is transparent and lilac-blue, violet or pink. The stones sometimes resemble pink topaz but are lighter and softer. Photo credit: Eurico Zimbres

Labradorite (M)

Its uncut color is a dirty grey. But when cut, it is usually blue in color. When placed at various angles, the color can change tremendously showing a metallic luster and beautiful sheen.

Lapis (MI)

Is a massive stone, typically of deep-blue color, but sometimes with mottlings of white. It is an expensive mineral and crystals with vivid color are even more valuable. It is dull except when given a polished surface.

Marcasite (M)

The real mineral is almost white and can resemble pale bronze. It is generally cut and mounted in a fashion to enhance its surface sparkle.

Mexican Fire Opal (G)

A variety of precious opal that is transparent to translucent and is reddish-brown to orange-red in background. Sometimes shows iridescence when viewed in certain directions.

Moldavite (C)

Is a variety of natural glass and is transparent and bottle-green to greenish-brown. It is used as a gemstone when faceted (cut) and polished.

Moonstone (MI, S)

An opalescent variety of orthoclase (a major rock forming mineral) and some other components give this stone a blue or white sheen known as a schiller.

Mother of Pearl (O, S)

Also known as nacre, it is an organic-inorganic composite material produced by some mollusks. It is strong, resilient and iridescent.

Onyx (MI, S)

Is a cryptocrystalline form of quartz. The colors of its bands range from white to almost every color. Pure black onyx is common, and perhaps the most famous variety, but not as common as banded onyx, which contains bands of white, tan and brown. Onyx is originally an Assyrian word meaning ring, and so could refer to anything used for making rings.

Opal (G)

There are two types of opal: 1) precious or noble that is iridescent and 2) a common opal characterized by a white, milky appearance with numerous sub-varieties.

Opal ranges from clear through white, gray, red, orange, yellow, green, shore, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare and dear, whereas white and greens are the most common.

Pearl (O, P)

The most valuable of all organic gems, pearls have been prized for their delicate iridescence and unique forms for at least 6,000 years. Pearls are formed when a foreign body such as a grain of sand or a parasite becomes trapped inside the shell of a mollusk. Pearls are relatively soft, but their concentric structure and organic binder give them great toughness. Due to the nature of pearls, they are susceptible to dehydration and exfoliation.

Peridot (MI)

Is a variety of the gem Olivine that is golden-green; but also ranges in shades from dark green to yellowish-green and can even be brown, black or colorless.

Resin (O)

Is a solid organic substance exuded from pin or fir trees. It is formless and translucent and generally yellow to brown.

Rose Quartz (MI, S)

Color ranges from pale pink to a deep rose-red.

Ruby (MI, P)

Its color ranges from pink to blood red. Only diamonds are harder than rubies. Lab-created rubies have been around since the 1890’s and are difficult to distinguish from natural.

Rutilated Quartz (Q)

Includes needle-like inclusions in some gemstones.

Sapphire (G, M)

Typically thought of as blue, sapphire can also be colorless, green, pink and a range of other hues. It is mined in parts of the US, India, Russia and countries throughout Africa. In ancient Greece and in the Middle Ages, there was a belief that sapphires cured eye diseases and served as an antidote against poison. It is September’s birth stone.

Smoky Quartz (MI, S)

Material ranging from pale brown to virtually black. Color results from natural radiation, and radioactive mineral grains ensconced in massive quartz are often surrounded by a ‘halo’ of smoky quartz.

Tanzanite (MI)

A variety of Epidote, a complex mineral, and is generally a pale-green color when first mined. However, they typically are bluish-violet and sometimes other hues.

Topaz (MI, S)

Has a glassy luster. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. They may be made white, gray, green, blue, pink or reddish-yellow and transparent or translucent.

Tourmaline (G)

Is found in a variety of colors due to its complicated and varied chemical composition. It is commonly found in black but other colors include blue, red, pink, green, brown and yellow.

Turquoise (MI, S)

Is an opaque, blue-to-green mineral that has been prized as a gem and ornamental stone for thousands of years owing to its unique hues. It is a water rich mineral yet only forms in dry regions of the world. It is extremely flexible and favored by artisans because it serves as an excellent carving surface.

Unakite (Q)

This semiprecious stone is a member of the quartz family and is a mixture of feldspar and epidote. Unakite exists in various shades of green and pink and is usually mottled in appearance. Use this stone for overcoming self-imposed blocks.

Wood (O)

Comes in an assortment of colors, however the natural hues of brown and black are most common.

Description sources include: Smithsonian Rock and Gem, wikipedia.com, An Illustrated Dictionary of Jewelry and Rocks and Minerals.

Types of Stones

Glossary of Stones