Archive for the cubic Category
-
Refractive Index : 1.728 (+0.012 – 0.008)
Optical Characteristic : SR, ADR
Specific Gravity : 3.64 (+0.02 – 0.12)
Formula : MgAI2O4
Crystal System : Cubic
Variety/Species : All
Species/Group : Synthetic spinel
Birefringence : none
Dispersion : .020
Hardness : 8
Toughness : good
Ultrasonic : Usually safe
Steam : usually safe
UV Long : Inert to strong
UV Short : Inert to strong
Pleochroism : None
Strength : N/A
Pleochroism [...]
-
Refractive Index : 1.718 (+0.017 – 0.008)
Optical Characteristic : SR
Specific Gravity : 3.60 (+0.10 – 0.03)
Formula : MgAI2O4
Crystal System : Cubic
Variety/Species : spinel
Species/Group : Spinel Group
Birefringence : none
Dispersion : 0.020
Hardness : 8
Toughness : good
Ultrasonic : Usually safe
Steam : usually safe
UV Long : Inert to strong
UV Short : Inert to weak
Pleochroism : None
Strength : N/A
Pleochroism Colors [...]
-
Refractive Index : 2.50 – 2.369
Optical Characteristic : SR
Specific Gravity : 4.05 (+0.05 – 0.15)
Formula : ZnS + Fe
Crystal System : Cubic
Variety/Species : Sphalerite
Species/Group : sphalerite Group
Birefringence : none
Dispersion : 0.156
Hardness : 3.5 to 4
Toughness : poor
Ultrasonic : Never
Steam : Never
UV Long : Inert to strong
UV Short : Inert to strong
Pleochroism : None
Strength : N/A
Pleochroism [...]
-
Refractive Index : 2.409
Optical Characteristic : SR
Specific Gravity : 5.13 (+0.02 – 0.02)
Formula : SrTiO3
Crystal System : Cubic
Variety/Species : strontium titanate
Species/Group : Synthetic Tausonite
Birefringence : none
Dispersion : 0.190
Hardness : 5 to 6
Toughness : fair
Ultrasonic : Usually safe
Steam : risky
UV Long : Inert
UV Short : Inert
Pleochroism : None
Strength : N/A
Pleochroism Colors : None
Heat : sensitive
Acids : [...]
-
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 : [...]
-
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 [...]
-
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 : [...]
-
Refractive Index : 1.327
Optical Characteristic : SR
Specific Gravity : 2.79
Formula : NaF
Crystal System : Cubic
Variety/Species : All
Species/Group : Villiaumite
Birefringence : Anomalous
Dispersion :
Hardness : 2 to 2.5
Toughness : Poor
Ultrasonic : Never
Steam : Never
UV Long : Inert
UV Short : Inert
Pleochroism : Anomalous
Strength : Strong
Pleochroism Colors : None
Heat : Sensitive
Acids : Sensitive
Light : Stable
Polish Luster : Vitreous
Fracture [...]
-
Natural Spinel Gemstone
Refractive Index : 1.718 (+0.017 – 0.008)
Optical Characteristic : SR
Specific Gravity : 3.60 (+0.10 – 0.03)
Formula : MgAI2O4
Crystal System : Cubic
Variety/Species : Spinel
Species/Group : Spinel Group
Birefringence : none
Dispersion : 0.020
Hardness : 8
Toughness : good
Ultrasonic : Usually safe
Steam : usually safe
UV Long : Red, orange and pink : Inert to weak red to [...]