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Name Origin | Derived fron Greek aktis meaning ray, due to its fibrous nature |
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Chemical Formula | Ca2(Mg,Fe)5Si8O22(OH)2 |
Color | Pale to dark green, blackish green, black |
Transparency | translucent to transparent |
Hardness | 5.5 on the Mohs scale |
Crystal System | Monoclinic; bladed crystals, often twinned |
Pleochroism | moderate, yellow to dark green (in stones that are transparent) |
Cleavage | perfect along {110}, often fibrous nature, brittle |
Specific Gravity (SG) | 3.05 |
Lustre | vitreous to dull |
Occurrence: Contact metamorphic limestones and dolomites; magnesium-rich limestones and ultrabasic rocks; regionally metamorphosed rocks.
Note: Actinolite is a member of a series that contains varying amounts of iron and magnesium. Tremolite is the Mg end, and ferroactinolite the Fe end, with actinolite in the middle. Actinolite is easy to cleave and hard to cut and would make a very poor gemstone. Actinolite is the chief constituent of nephrite (jade).
Note: Actinolite is a member of a series that contains varying amounts of iron and magnesium. Tremolite is the Mg end, and ferroactinolite the Fe end, with actinolite in the middle. Actinolite is easy to cleave and hard to cut and would make a very poor gemstone. Actinolite is the chief constituent of nephrite (jade).
Read more about other color stones
Adamite
Amber
Algodonite
Andalusite
Amblygonite
Aragonite
Azurite
Barite
Tanzanite
Chert
Crodierite
Hauyne
Inderite
Topaz
Adamite
Amber
Algodonite
Andalusite
Amblygonite
Aragonite
Azurite
Barite
Tanzanite
Chert
Crodierite
Hauyne
Inderite
Topaz
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