Tremolite

Tremolite is actually a group of minerals that occur in white, light to dark gray, light yellow, light to dark green, light pink and light purple colors. The name Tremolite is also used in referring to the colorless to white, sometimes gray variety of the group.

Tremolite minerals are composed of calcium magnesium iron silicate hydroxide [Ca2 (Mg, Fe) 5Si8O22(OH) 2]. A pure form of Tremolite without any iron impurity has the typical creamy white color. Iron content in Tremolite will raise its specific gravity, index of refraction and darken the color.

Apart from the white variety, members of the Tremolites known to collectors and people in the gemstone industry include: Chrome-Tremolite, a variety containing chromium which gives it a deep green color; Hexagonite, a beautiful pink to lilac variety and Mountain Leather or Mountain Cork, a fibrous Tremolite which forms a felted mass that has all the appearances and feel of a piece of cloth.

The Tremolite mineral has been discovered in various locations including the area around Wilberforce, Ontario, Canada; De Kalb, St Lawrence Co., New York; California; Arizona and Canaan, Connecticut, USA; Tyrol and Piemonte, Italy; Tremola Valley, Switzerland; Tanzania and Finland. Tremolite was named after the first locality it was discovered in, the Tremola Valley.

Tremolite specimens can be translucent to transparent and are vitreous in luster. They rank 5 to 6 on the Moh’s Scale of Hardness with a Specific Gravity of 2.9 to 3.1. Fine crystals can be perfectly clear. With its good hardness and luster, Tremolite will make a nice jewelry stone.