A green to black mineral composed of calcium-magnesium silicate. Actinolite mixed with tremolite forms Nephrite, a translucent green mineral that is one of the forms of Jade. Actinolite deposits occur in Great Britain, Russia, Japan, China, Austalia, Brazil, Canada (British Columbia), and the U.S. (Alaska, California, Wyoming and Vermont). The transparent to opaque stone is used as a filler in paints and ceramics.
Synonyms and Related Terms
Physical and Chemical Properties
- Monoclinic system with fibrous or granular crystalline masses.
- Luster = vitreous to silky.
- Streak = colorless
- Cleavage is perfect in two directions; fracture is splintery
Resources and Citations
- Mineralogy Database: actinolite
- C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
- Wikipedia at http://en.wikipedia.org/wiki/Actinolite (accessed Sept. 2007)
- MinDat.org: actinolite (accessed Sept. 2007); sp. grav.=3.03-3.24; streak=white; cleavage=good in one direction