1 Astrology
1.1 Origin
Not Available, Southern and central Africa
Southern and central Africa
1.2 Color
Violet, Black
Black, Reddish, gray, Red
1.3 Streak
gray, White, gray, White
Black, Brown, Reddish, Red
1.4 For which Rashi?
Not Available
Aries, Aquarius, Aries, Aquarius, Aries, Aquarius
1.5 Planet
1.6 Element of Planets
Not Available
Not Available
1.7 How to Wear?
1.7.1 Finger
Not Available
Not Available
1.7.2 Ring Metal
Not Available
Not Available
1.8 Energy
1.9 Deities
1.10 Not to wear with
Not Available
Not Available
1.11 Powers
1.12 Birthstone
1.12.1 Planetary
Not Available
Not Available
1.12.2 Talisman
Not Available
Not Available
2 Physical Properties
2.1 Tenacity
2.2 Solubility
Not Available
Not Available
2.3 Durability
Not Available
Not Available
2.4 Specific Gravity
2.5 Fracture
Handbook of mineralogy (2001)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
2.6 Cleavage
None
None, may show partings on {0001} and {10 1 1}
2.7 Mohs Hardness
2.8 Chemical Composition
Na x[Fe2+2(Al,Fe3+ )]Al 6(BO 3) 3Si 6O 18(OH) 4Anthony et al , Handbook of mineralogy (2001)
Fe 2O 3Arthur Thomas , Gemstones (2009)
3 Optical Properties
3.1 Luster
3.2 Pleochroism
Strong: pale lavender dark blueAnthony et al
O = brownish red; E = yellowish red
3.3 Dispersion
3.4 Transparency
TranslucentAnthony et al, Translucent
OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
3.5 Refractive Index
Not Available2.690-3.220
1
3.25
3.6 Optic Character
Not Available
Not Available
3.7 Crystal System
Trigonal Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3m
Trigonal
3.8 Birefringence
Not Available0.280
0
0.296
3.9 Clarity
TranslucentAnthony et al
OpaqueHerve Nicolas Lazzarelli
4 Benefits
4.1 Physical
4.1.1 Neurological
Not Available
Not Available
4.1.2 Cardiovascular
Not Available
Not Available
4.1.3 Respiratory
Not Available
Not Available
4.1.4 Reproductive
Not Available
Not Available
4.1.5 Digestive
Not Available
Not Available
4.2 Psychology
Not Available
Not Available
4.3 Healing
Not Available
Not Available
4.4 Qualities Associated
Not Available
Not Available