Origin
China, Canada
Southern and central Africa
Color
Green, Yellow, Brown, White, gray, Black
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Specific Gravity
2.90-3.10
2.50-2.80
Fracture
Splintery, Granular
-
Mohs Hardness
6-6.5
5-6.5
Chemical Composition
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)
Luster
Vitreous, Greasy
-
Transparency
Translucent
Transparent
Refractive Index
1.600-1.627
1.531-1.600
Crystal System
monoclinic
-
Birefringence
0.027
0.004-0.037
Clarity
Translucent
Transparent
Neurological
Aids in mental clarity and focus
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Psychology
Emotional Balance
Creativity
Healing
Physical healing
-
Qualities Associated
Healing
Creativity