APPLICATIONS: | Limited to some asbestos uses and as mineral specimens. |
ASSOCIATED MINERALS: | Talc, cordierite and phlogopite. |
CHEMICAL STRUCTURE: | (Mg, Fe)7Si8O22(OH)2 , Magnesium Iron Silicate Hydroxide. |
CLASS: | Silicates. |
CLEAVAGE: | Good in two directions at 56 and 124 degree angles forming wedge shapes fragments. |
COLOR: | Usually various shades of brown such as yellow-brown, green-brown or brownish-gray, but also green, off-white or gray. |
CRYSTRAL HABITS: | Prismatic often aggregated crystals and fibrous, asbestos-like masses. |
CRYSTAL SYSTEM: | Orthorhombic, 2/m 2/m 2/m. |
FIELD INDICATORS: | Crystal habit, fracture, cleavage, color, streak and hardness. |
FRACTURE: | Easy and splintery. |
GENERAL INFORMATION: | Weakly pleochroic and a blue schiller effect is seen in some specimens from Butte, Montana. |
GEOGRAPHY: | Butte, Montana; Delaware County, Pennsylvania; California; Arizona and Franklin County, North Carolina, USA; Ontario, Canada; Greenland; Kongsburg, Norway and Italy. |
GROUP: | Amphibole. |
HARDNESS: | 5.5 - 6. |
LUSTER: | Vitreous to dull or silky in fibrous forms. |
TRANSPARENCY: | Translucent to opaque. |
SPECIFIC GRAVITY: | 2.9 - 3.4. |
STREAK: | Gray. |
SUBCLASS: | Inosilicates. |
