Magnesite Ivoryite Howlite Turquoise

In the lapidary and gemstone world, Magnestie, Ivoryite, Howlite and Turquoise are all natural gemstones in their own right. But how does one tell the difference and know which is which, since there are so many different stones with the same type of names and looks. For a lesson in geology and lapidary, I posed the questions to my resident Gemologist for clarification.

Turquoise is an opaque, blue-to-green mineral that is ahudrous phosphate of copper and aliminium. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. In recent times turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the market, some difficult to detect even by experts. The substance has been known by many names, but the word turquoise was derived around the 16th century from the French Language either from the word for Turkish (Turquois) or dark-blue stone (pierre turquin). This may have arisen from a misconception: turquoise does not occur in Turkey, but was traded at Turkish bazaars to Venetian merchants who brought it to Europe. It originated in China. Turquoise has a hardness of 5 to 6 on the Moh's scale. Tuerquoise is found throughout the American Southwest and Mexico; in Virginia and Pennsylvania, USA; throughout the Middle East except for Turkey and Iraq, China and Western Australia.

Magnesite is magnesium carbonate. Dolomite is almost indistinguishable from magnesite. Magnesite occurs as veins in and an alteration product of ultramafic rocks, serpentinite 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. Magnesite can be used as a slag former in steelmaking furnaces. Magnesite also forms within a crystal group that have the rhombic habit. Magnesite is usually associated with calcite, dolomite, aragonite, strontianite and serpentine. Magnesite is 3 to 4-1/2 on the Moh's scale. Magnesite in of itself does not ordinarily form good crystals, or solid pieces of rock, but can make up a substantial portion of some rock types. If it does form crystals or hard stones, it is about a 7 on the Moh’s scale. Stones hard enough for lapidary and jewelry purposes are found in Bisbee, Warren District Mule Mine, Cochise Co, AZ: Bangge Xainza, Nagchu Prefecture, Tibet: Jianchanling Mine, Western Qinling Tibet: Jianchaling Mine, Lueyang Co, Shaanxi Province, China: and Saertuohai, Tuoli Tacheng Prefecture, Xinjiang, China.

Ivoryite is a great substitute for ivory. Ivoryite is a synthetic material made to look and feel like Ivory, an animal friendly alternative! A substance called Ivoryite, which is a Misnomer, 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. There is actually no specific mineral named Ivoryite, it is a misnomer given to harder varieties of Magnesite. Found all the same locations as Magnesite or Howlite.

Howlite is a calcium borosilicate hydroxide is a silicate mineral found in evaporite deposites. Howlite was discovered at Tick Canyon, California in 1868 by Henry How (1828 - 1879), a Canadian chemist, geologist, and mineralogist. In appearance, it is white with fine grey or black veins in an erratic, often web-like pattern, and is opaque with a sub-vitreous luster. Its structure is monoclinic with a Moh’s hardness of 3.5 and lacks regular cleavage. Howlite is commonly used to make decorative objects such as small carvings or jewelry components. Because of its porous texture, howlite can be easily dyed to imitate other minerals, especially turquoise because of the superficial similarity of the veining patterns. The dyed howlite (better known as Ivoryite or Magnesite) is marketed as turquenite. Howlite is also sold in its natural state, sometimes under the misleading trade names of "white turquoise" or "white buffalo turquoise", or the derived name "white buffalo stone". Noe “sacred White Buffalo Turquoise does exist in one mine in Nevada). Howlite is found in its natural state only in the Southwestern United States; Nova Scotia, Canada; Germany and Turkey. A accepted misnomer for a variety of Magnesite.

Appaloosa Stone or Wild Horse Magnesite is a natural Gemstone from a single source on an Indian Reservation near Bisbee, AZ. There is much discussion over this material, because it is too hard to be a magnesite (ivoryite or howlite), so most lapardists consider it to be a jasper deposit mixed in with the turquoise. A standard explanation of this material is “Wild Horse, often called Appaloosa Jasper or Magnesite, is a one source stone. The Navajos like using this unusual stone in their Jewelry. It has shadow hues in it, along with lots of lined matrix, and lots of white, all giving it an striking effect. Wild Horse “stone” completely captivate whoever gazes upon it!“