Southwest Affinity's gemstone choices

Gemstones have been used by cultures, around the world, for centuries. Some stones have been used as items of personal adornment, for their beauty. Some were used as currency and still others were used for their purported medicinal properties. As an example, Ancient Greeks used the amethyst, a variety of the quartz gemstone group, to ward off the effects of drinking "too much wine." Opal has been and is still used by various cultures to symbolize "good luck". A diamond symbolizes wealth and prosperity.

Sleeping Beauty Turquoise necklace and watch handcrafted by Native American silversmiths.

Sleeping Beauty Turquoise is known for its pure blue turquoise stones that have little to no matrix. It ranges from a sky blue to a deep royal blue in color.

Appearance: Light to dark blue, greenish blue to dark green in color and may show dark veins and or splotches of matrix. Cause of color is Copper in blue Turquoise and Copper and Iron in green Turquoise. Stones are semi-translucent to opaque.

Hardness: 5 - 6 (The Mohs scale of Gemstone hardness is from 1-10, 1 being soft like Talc and 10, the hardest, like diamond).

Common Enhancements/Treatments Include: plastic impregnation, wax impregnation, dyeing blue or green, dyeing with black shoe polish to enhance the matrix, backing with thin pieces of epoxy to add thickness, filling cavities with metal-loaded epoxy to imitate pyrite inclusions.

Common Materials Mistaken For Or Used To Imitate Natural Turquoise: synthetic turquoise, glass, dyed Howlite, plastic, Variscite, Amazonite, Pectolite, Prosopite, Serpintine.

Major Worldwide Sources: Southwestern United States - historically, Nevada, Arizona, New Mexico and Colorado, Australia, Iran, Chile, China and Mexico.

Disclosures: Avoid high heat and chemicals. Perspiration, skin oils, soaps, hand lotions and cosmetics may turn blue Turquoise dark green. Recommend-removing jewelry before washing hands.

To learn more about turquoise visit this article Facts about turquoise at about.com

Appearance: What is usually considered "Precious Opal" is Opal that is white, gray or dark gray in body color and it will exhibit "Play-of-Color", what some call fire. Natural "Black Opals", the most highly prized Precious Opals, are actually any Opal that has a grayish to very dark gray body color. Opal that is called "Common Opal" is any Opal other than Precious Opal. It can have virtually any body color - white, gray, black, blue, green, brown, red, orange but it will not exhibit any phenomena or Play-of-Color. Opals are transparent to opaque in their appearance. The phenomena in Opal is called "Play-of-Color" but can also exhibit other phenomena like "Asterism" (stars) and "Chatoyancy" (cats-eye effect).

Commonly Used Opal Names: White Opal, Black Opal, Crystal Opal, Fire Opal, Cherry Opal, Jelly or Water Opal, Boulder Opal, Opalized Wood and Opalized Shell.

Common Names Based On The Appearance Of The "Play-of Color": Pin fire (very small pin points of color), Harlequin (very large flakes of color), Flame Opal, Flash Opal, Peacock Opal and Lechoses Opal.

Common Enhancement/Treatments Include: plastic, oil or wax impregnation for improving the "Play of Color". Treatments with silver nitrate, sugar, aniline dye and smoke impregnation are used to create the appearance of "Black Opals". Also reflective foil is sometimes used as a backing to improve the "Play-of-Color". "Slate" is sometimes used as a backing for very thin pieces of Opal. When this is done it is called an "Opal Doublet". An "Opal Triplet" is when a backing is used along with a clear Quartz cap on top of a very thin piece of Opal, giving the impression of a large well- formed piece of Opal.

Common Materials Mistaken For Or Used To Imitate Natural Opal: Synthetic Opal, Glass, Chalcedony, and Plastic. Synthetic Opal has the same chemical composition and structure as natural Opal but it is created in a laboratory. There are only a couple gemological tests for separating Natural and Synthetic Opal, magnification and possibly testing for phosphorescence.

Major worldwide Sources: The high quality and most famous Precious Opals come from the Coober Pedy and Andemooka deposits of Southern Australia. Other sources are Brazil, Mexico, US, Honduras, Indonesia, Japan, Tanzania and Czechoslovakia.

Disclosures: Avoid heat, sudden changes in temperature, hydrofluoric acid and any caustic alkalies. Opals are fragile. Avoid any sharp blows. Return to top

Composed of Lazurite, Calcite and Pyrite and may contain some Sodalite, Hauynite, Diopside, Augite, Mica and Hornblende, in varying amounts. (chemical composition depends on mineral content). Lapis is the only ordinary "Rock" that is considered a Gemstone.

Appearance: Semi-translucent to opaque. Medium to dark, greenish blue to violet blue in color, often with brassy colored Pyrite flecks and/or white to gray calcite inclusions.

Common Enhancements/Treatments Include: dyeing to improve color and disguise Calcite inclusions. Impregnation or coating with wax to improve color and seal dye.

Common Materials Mistaken For Or Used To Imitate Natural Lapis: dyed Chalcedony, dyed Howlite, Sodalite, Gilson Imitation Lapis (man made) and Lazulite.

Major Worldwide Sources: Afghan Lapis, Finest quality. Intense, evenly colored medium dark, slightly violet blue with little or no pyrite and no white calcite veining.

Siberian/Russia, Next best quality. Various tones and intensities of blue and contains Pyrite. Chilean, Least valuable. Contains numerous white calcite inclusions. Some have given this quality of Lapis the name "Denim Lapis" in recent years.

Picture from Mystic Merchant where these stones are available for purchase

SUGILITE (SOO-jih-lite) (K,Na)(Na,Fe)2(Li2Fe)Si12O30 Sometimes called Lavulite or Royal Lavulite and Royal Azel.

Appearance: Semi-transparent to opaque, red-purple to bluish purple, rarely pink. Semitransparent stones are deemed the most valuable.

Common Materials Mistaken For Sugilite: Charoite and Amethystine Chalcedony.

VARISCITE (VARE-iss-site) AIPO4.2H2O Sometimes called Utahlite, Amatrice, Sabalite or Trainite.

Appearance: Translucent to opaque, light to medium dark yellow green to medium dark bluish green, often with yellowish or brown matrix.

Common Materials Mistaken For Variscite: Green Turquoise, Serpentine, Jadeite, Nephrite and Malachite

Disclosures: Avoid acids, heat, ultrasonic cleaners, steam cleaners and rough handling. Return to top

Common Enhancements/Treatments: dyeing, wax or plastic impregnation and irradiation. Dyeing and irradiation are used to produce various colors and is very common. Black Onyx is normally milky or white Onyx dyed black.

Common Materials Mistaken for Onyx: Natural and dyed Chalcedony along with Alabaster.

Major Sources Worldwide: Mexico and the US. Also England, France, Germany, Iceland, USSR and Pakistan.

Disclosures: Avoid rough handling, heat, steam cleaners, ultrasonic cleaners and any chemicals. Advise that Onyx is almost always dyed. Mexican Jade is dyed green Onyx. Return to top

Organic Gemstones

CORAL (CORE-ul) (Calcareous Coral) CaCO3 (in the form of Calcite) and (Conchiloin Coral) C32H48N2O11 (a protein material). There are two types of coral used in jewelry: calcareous and conchiolin). Please note: the beautiful pink or deep red Ox Blood coral from the Mediterranean Sea, that is used in Native American Jewelry, is a Calcareous Coral.

Appearance: Calcareou Coral semi-translucent to opaque. Light to darkish pink through dark red. Also orange, white and cream colors and sometimes blue and purple. Conchiolin Coral semi-translucent to opaque. Can be black, gray, dark brown and yellow.

Common Enhancements: Calcareous-Dyeing, which deepens or changes the color and impregnation with epoxy, which will hide surface cracks and fills cavities, in lower quality Coral. Conchiolin-Bleaching in Hydrogen Peroxide will turn Black Coral a golden yellow color. Please note, this is a very common practice.

Common Materials Mistaken For Or Used To Imitate Natural Coral: For Calcareous Coral-Imitation (man made) Coral, Plastic, Shell, Howlite, Ivory, Fossil Ivory, Onyx/Calcite. For Conchiolin Coral-Plastic, Jet, Chalcedony.

Major Worldwide Sources: Calcareous Coral-Mediterranean Sea, Australia, Philippines, Japan, Algeria, France, Italy, Morocco Tunisia and to a lesser extent Taiwan, US and Ireland. Conchiolin Coral-Hawaii and Australia.

Disclosures: Calcareous and Conchiolin Coral-Avoid heat, chemicals and acids. Handle with care. Note the possibility of enhancements. Return to top

Pink Mussel

Appearance: Translucent to opaque. Commonly white but can be gray, brown, yellow, orange, pink and purple. Often with layered or patterned coloring.

Common Materials Mistaken For Or Used To Imitate Natural Shell: Coral, Plastic, Calcareous Concretions and Chalcedony.

Major Worldwide Sources: The majority of the shell used for jewelry comes from tropic and sub-tropic waters, worldwide.

Disclosures: Avoid rough wear, heat, chemicals and acids. Keep Conch Shell out of direct light. Return to top

JET Organic material. Compact form of Lignite Coal, primarily carbon with some hydrogen and oxygen.

Common Materials Mistaken For Jet: plastic, Black Coral, dyed Chalcedony, Vulcanite (hard rubber/old phonograph records).

Natural Horn: (Organic/Protein Material) Buffalo, bull, stag, rhinoceros, etc.

Disclosures: Avoid rough handling, heat and chemicals and with prolonged exposure to sunlight, may gradually bleach. Never use ultrasonic or steam cleaner. Return to top

Antique Hand Carved Ivory Chinese Card Case. Photo provided to Southwest Affinity by One of a Kind Antiques

Ivory: (65% mineral and 35%protein material) Mostly calcium phosphate with collagen and elastin.

Common Enhancements/Treatments: bleaching (to remove stains or lighten color) and dyeing (to create the appearance of antique Ivory).

Major Worldwide Sources: Please note there are different kinds of Ivory and some are from, living, protected species. There is elephant, hippopotamus, walrus, sperm whale, narwhale, wart-hog ivory, along with the fossil ivory's- Fossil Wooly Mammoth, Mastodon and Fossil Walrus Ivory. Fossil ivory is unlike fossilized dinosaur bone, where, over time, minerals replace the actual done material. Dinosaur bone is actually rock, usually in the Quartz family of gemstones, like Jasper. Fossilized Ivory has retained most if not all of it original structure. It has just about the same properties as modern ivory. Its original material has not degraded away and /or been replaced by other minerals. Fossil ivory can be found wherever there were Prehistoric Mammoths and Walrus. Most, used in jewelry today, comes from the North American continent and Eastern Europe (Siberia) where you can find it by the ton.

Disclosures: Never use steam or ultrasonic cleaners. Avoid chemicals and heat. Sunlight will age or turn natural ivory yellow. Avoid rough wear.

As you can see from the above materials, that can be used to imitate natural gemstones, always purchase your gemstones and jewelry from a reliable source. Only a small portion of what is on the market today is 100% natural and untreated. Gemstones are irradiated, dyed, heated, waxed, pressurized, stabilized, expoyed, created in laboratories and imitated. Only by careful examination, knowing your suppliers and asking the right questions can you assure that your purchase will be a natural genuine gemstone.

For more information on gemstones, contact: The GIA Library at 800-421-7250 ext. 4046 or 4068 or The GIA Gem Instruments and Books Store at 800-421-8161.

Other stones that are used by Southwest Affinity and not mentioned in the above article:

When discovered in the Dry Creek Mine (Note: not it's name today) in the Shoshone Indian Reservation near Battle Mountain, Nevada in 1993, they (the discoverers) were not sure what it was. Because of its hardness, it was decided to have it assayed. Their suspicious proved correct. It was, in fact, white turquoise. It was not until 1996, however, that it was finally made into jewelry. The Shoshone Indians are not known for jewelry work and, as a consequence, the Shoshone sell or trade the white turquoise to the Navaho in Arizona who work it into jewelry. Because white turquoise is as rare as the white buffalo, the Indians call it "White buffalo" turquoise. Turquoise gets its color from the heavy metals in the ground where it forms. Blue turquoise forms where there is copper present (most Arizona turquoise). Green turquoise forms where iron is present (most Nevada turquoise). White turquoise, where there are no heavy metals present, turns out to be rare. To date no other vein of white turquoise has been discovered anywhere else. When this current vein runs out that will be the last of it.

Gemstones

By Michael Anthony Cheatham, Gemologist, FJC (GIA), and George "Shukata" Willis, President IAEA, the Indian Arts Education Association.

Organic Gemstones