Archive for the Tetragonal Category

  • Stolzite

    Refractive Index : 2.27 – 2.19

    Optical Characteristic : DR, U-

    Specific Gravity : 8.34 – 7.90

    Formula : PbWO4

    Crystal System : Tetragonal

    Variety/Species : All

    Species/Group : Stolzite

    Birefringence : 0.08

    Dispersion :

    Hardness : 2.5 to 3

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert

    UV Short : Inert

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat : sensitive

    Acids : sensitive

    Light [...]

  • Anatase

    Refractive Index : 2.564 – 2.488

    Optical Characteristic : DR, U-

    Specific Gravity : 3.97 – 3.82

    Formula : TiO2

    Crystal System : Tetragonal

    Variety/Species : Anatase

    Species/Group : Titanium Oxide

    Birefringence : .067-.046

    Dispersion : .213-.259

    Hardness : 5.5 to 6

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert

    UV Short : Inert

    Pleochroism : 2 or 3 Colors

    Strength : Weak to strong

    Pleochroism Colors [...]

  • Tugtupite

    Refractive Index : 1.502-1.496

    Optical Characteristic : DR, AGG

    Specific Gravity : 2.36 +.22 -.06

    Formula : Na4AIBeSi4O12CI

    Crystal System : Tetragonal

    Variety/Species : Tugtupite

    Species/Group : Sodalite group

    Birefringence : Not detectable

    Dispersion : none

    Hardness : 4 to 6.5

    Toughness : good

    Ultrasonic : risky

    Steam : Risky

    UV Long : Moderate to strong

    UV Short : Modarate to strong

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat [...]

  • Wardite

     

    Refractive Index : 1.604 – 1.586

    Optical Characteristic : DR, uniaxial negative

    Specific Gravity : 2.87-2.81

    Formula : NaAI3(PO4)2(OH)4.2(H2O)

    Crystal System : Tetragonal

    Variety/Species : All

    Species/Group : Wardite

    Birefringence : 0.009

    Dispersion : N/A

    Hardness : 5

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert

    UV Short : Inert

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat : Sensitive

    Acids : Sensitive

    Light : Stable

    Polish Luster [...]

  • Zircon

    Refractive Index : 1,984 – 1.925 (+ 0.040 – 0.145)

    Optical Characteristic : DR, Uniaxial positive

    Specific Gravity : 4.70 (+ 0.03 – 0.80)

    Formula : ZrSiO4 +Fe,U,Th,Hf

    Crystal System : Tetragonal

    Variety/Species : Zircon is classified as high, medium or low type (also called as alpha, beta or gamma type), depending on the extent of structural breakdown. But in [...]