Tremolite

Chemistry: Calcium magnesium silicate
Crystal system: Monoclinic; in compact mass as nephrite; long bladed crystals; fibrous aggregates often radiated; twinning common.
Color: Transparent to opaque; hexagonite: rare pink variety (Mg); phenomenon: greenish chatoyancy: tremolite cat’s eye.
Hardness: 6.5 - 6
Cleavage: Good: in 2 directions; fracture: brittle, uneven.
Specific gravity: 2.976; 2.98
Refractive index: 1.62 mean; 1.60 – 1.63; 0.027.
Luster: Vitreous.
Dispersion:-
Dichroism: -
Occurrence: In metamorphosed dolomites or ultrabasic rocks; Burma, Taiwan, Canada, USA.

Notes
An end member in the tremolite-actinolite series of the amphibole group; transparent specimens faceted; translucent to opaque specimens carved or cut cabochon.