Tuesday, July 12, 2011

SOUTHWESTERN FLAIR -- Wild Horse Magnesite and Ivoryite !

From the deserts of the Southwesten United States comes a exciting gemstone called by many Wild Horse Turquoise. Although coming out of the same mines as Turquoise, its characteristic is a reddish-brown matrix surrounding a snow white background. This is a beautiful and very extraordinary combination. However, the correct identification of the material is Magnesite, not Turquoise since there is no cupric in it to give the blue, blue-green or green coloration that makes Turquoise so famous. But wheather called Wild Horse Magnesite or Wild Horse Turquoise, it is from the same locations and is extremely hard to find but make beautiful jewelry.

You are looking at true Southwest. The colors of the desert - tans and browns - are predominent in the Sterling Silver bezel set Wild Horse Magnesite triangular pendant. Magnesite barrels and Ivoryite rondels are interlaced with sterling silver and chain links to give this 19 inch necklace with 2 inch extender its fantastic look. Magnesite and Ivoryite are further paired in teh 1 inch long Leverback earrings that complete the set.

Magnesite occurs as veins in and an alteration product of ultramafic rocks like serpentinite, turquoise and other magnesium rich rock types in both contact and regional metamorphic terranes. These Magnesites often are cryptocrystalline and contain silica as opal or chert. Magnesite is also present within the regolith above ultramafic rocks as a secondary carbonate within soil and subsoil, where it is deposited as a consequence of dissolution of magnesium-bearing minerals by carbon dioxide within groundwaters. Some of the best Magnesite deposits that can produce gemstone quality material are co-located with Turquoise deposits in the southwestern United States.

Ivoryite is a great substitute for ivory. It is a sedimentary precipitate of magnesium, calcium and silica. It is 5 to 5-1/2 on the Moh's scale, which makes it slightly harder than ivory. Ivoryite can be worked with metal tools, but cuts effortlessly with diamond tools. Polishes well with diamond, tin oxide, cerium oxide or white rouge. Excellent material for inlay, cabochons and small carvings. Do not confuse Ivoryite with Ivorite, whic is a black tektite material from Africa. The majority of Ivoryite currenly comes from the western United States, especially Colorado and California.