Archive for the Garnet Group Category
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Refractive Index : 1.888 + 0.007 – 0.033
Optical Characteristic : SR, ADR
Specific Gravity : 3.84 + 0.03 – 0.03
Formula : Ca3Fe+++2(SiO4)3
Crystal System : Cubic
Variety/Species : Ugrandite/Andradite
Species/Group : Garnet Group
Birefringence : None
Dispersion : 0.057
Hardness : 6.5 to 7
Toughness : Fair to good
Ultrasonic : Uaually safe
Steam : Never
UV Long : Inert
UV Short : Inert to moderate
Pleochroism : [...]
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Tsavorite Garnet
Refractive Index : 1.740 + 0.020 – 0.070
Optical Characteristic : SR, ADR
Specific Gravity : 3.61 + 0.12 – 0.04
Formula : Ca3AI2(SiO4)3
Crystal System : Cubic
Variety/Species : Ugranite/Grossular
Species/Group : Garnet group
Birefringence : None
Dispersion : 0.028
Hardness : 7 to 7.5
Toughness : Fair to good
Ultrasonic : Usually safe
Steam : Never
UV Long : Inert to weak
UV Short : Inert [...]
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Natural Uvarovite Gemstone
Refractive Index : 1.870 – 1.740
Optical Characteristic : SR
Specific Gravity : 3.80 – 3.40
Formula : Ca3Cr2Si3O12
Crystal System : Cubic
Variety/Species : Ugrandite
Species/Group : Garnet Group
Birefringence : N/A
Dispersion : N/A
Hardness : 7 to 7.5
Toughness : Poor
Ultrasonic : Never
Steam : Never
UV Long : Inert
UV Short : Inert
Pleochroism : None
Strength : N/A
Pleochroism Colors : None
Heat : [...]
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Refractive Index : 1.833 (+ 0.010 – 0.010)
Optical Characteristic : SR
Specific Gravity : 4.60 to 4.50
Formula : Y3AI5O12
Crystal System : Cubic
Variety/Species : Yttrium Aluminum Garnet
Species/Group : Garnet (Man-made)
Birefringence : None
Dispersion : 0.028
Hardness : 8.25
Toughness : Good
Ultrasonic : Uaually safe
Steam : Usually safe
UV Long : Inert to strong
UV Short : Inert to strong
Pleochroism : None
Strength : [...]
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Star Almandite
Refractive Index : 1.790 (+0.030 – 0.030)
Optical Characteristic : SR, ADR
Specific Gravity : 4.05 (+0.25 – 0.12)
Formula : Fe++3AI2(SiO4)3
Crystal System : Cubic
Variety/Species : Almandite
Species/Group : Garnet group
Birefringence : none
Dispersion : 0.024
Hardness : 7 to 7.5
Toughness : Fair to good
Ultrasonic : Usually safe
Steam : Never
UV Long : Inert
UV Short : Inert
Pleochroism : None
Strength : N/A
Pleochroism [...]
