Archive for the Uncategorized Category

  • Snowflake obsidian

    Refractive Index : 1.490 (+0.020 – 0.010)

    Optical Characteristic : SR, ADR

    Specific Gravity : 2.40 (+0.10 – 0.07)

    Formula : Mostly silica.

    Crystal System : Non-crystalline

    Variety/Species : obsidian

    Species/Group : glass-natural

    Birefringence : none

    Dispersion : N/A

    Hardness : 5 to 5.5

    Toughness : Fair to good

    Ultrasonic : Usually safe

    Steam : risky

    UV Long : Inert

    UV Short : Inert

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors [...]

  • Sodalite

    Refractive Index : 1.483 (+0.004 – 0.004)

    Optical Characteristic : SR, AGG

    Specific Gravity : 2.25 (+0.15 – 0.10)

    Formula : Na8AI6Si6O24CI2

    Crystal System : Cubic

    Variety/Species : sodalite

    Species/Group : Sodalite group

    Birefringence : none

    Dispersion : none

    Hardness : 5 to 6

    Toughness : poor

    Ultrasonic : Never

    Steam : risky

    UV Long : Inert to weak

    UV Short : Inert

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : [...]

  • Tektite

    Refractive Index : 1.54 – 1.46

    Optical Characteristic : SR, ADR

    Specific Gravity : 2.96 – 2.21

    Formula : Mostly silica.

    Crystal System : Non-crystalline

    Variety/Species : Tektite

    Species/Group : glass-natural

    Birefringence : none

    Dispersion : N/A

    Hardness : 5.5 to 6.5

    Toughness : Fair to good

    Ultrasonic : Usually safe

    Steam : risky

    UV Long : Inert

    UV Short : Inert

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat [...]

  • Vlasovite

     

    Refractive Index : 1.628 – 1.607

    Optical Characteristic : DR, biaxial negative

    Specific Gravity : 2.97

    Formula : Na2ZrSi4O11

    Crystal System : Monoclinic

    Variety/Species : All

    Species/Group : Vlasovite

    Birefringence : 0.021

    Dispersion :

    Hardness : 6

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert

    UV Short : Inert to moderate

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat : Sensitive

    Acids : Sensitive

    Light : [...]

  • Rose Quartz

    Refractive Index : 1.553 – 1.544 (very constant)

    Optical Characteristic : DR Uniaxial positive or AGG

    Specific Gravity : 2.651 (+0.04 – 0.01)

    Formula : SiO2

    Crystal System : Trigonal

    Variety/Species : Rose quartz

    Species/Group : Quartz

    Birefringence : 0.009

    Dispersion : 0.013

    Hardness : 7

    Toughness : good

    Ultrasonic : Usually safe

    Steam : risky

    UV Long : Inert to weak

    UV Short : Inert to weak purple

    Pleochroism : [...]

  • Achroite

     

    Refractive Index : 1.644 – 1.624 (+0.011 – 0.009)

    Optical Characteristic : DR U-

    Specific Gravity : 3.06 (+0.20 – 0.06)

    Formula : Na(Li,Al)3Al6(BO3)3Si6O18(OH)4

    Crystal System : Trigonal

    Variety/Species : Elbaite

    Species/Group : Tourmaline Group

    Birefringence : 0.018 to 0 .040

    Dispersion : 0.017

    Hardness : 7 to 7.5

    Toughness : Fair

    Ultrasonic : Risky

    Steam : Risky

    UV Long : Inert

    UV Short : Inert

    Pleochroism : None

    Strength : [...]

  • Amazonite

     

    Refractive Index : 1.530 – 1.522 (+0.004 – 0.004)

    Optical Characteristic : DR Biaxial negative , usually AGG reaction

    Specific Gravity : 2.56 (+ 0.02 – 0.02)

    Formula : KAlSi3O8

    Crystal System : Triclinic

    Variety/Species : Microcline Feldspar

    Species/Group : Feldspar Group

    Birefringence : 0.008

    Dispersion : None

    Hardness : 6 to 6.5

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert to weak [...]

  • Allanite

    Refractive Index : 1.828 – 1.640

    Optical Characteristic : DR B-

    Specific Gravity : 4.20 – 3.40

    Formula : (Y,Ce,Ca) 2 (Al,Fe+++) 3 (SiO4) 3 (OH)

    Crystal System : Monoclinic

    Variety/Species : Allanite

    Species/Group : Epidote Groupy

    Birefringence : 0.019 to 0.045

    Dispersion : 0.030

    Hardness : 6 to 7

    Toughness : Fair to poor

    Ultrasonic : Risky

    Steam : Never

    UV Long : Inert

    UV Short : [...]

  • Ametrine

    Refractive Index : 1.553 – 1.544

    Optical Characteristic : DR U+ , AGG

    Specific Gravity : 2.651 (+0.04 – 0.01)

    Formula : SiO2

    Crystal System : Trigonal

    Variety/Species : Ametrine

    Species/Group : Quartz

    Birefringence : 0.009

    Dispersion : 0.013

    Hardness : 7

    Toughness : Good

    Ultrasonic : Usually Safe

    Steam : Risky

    UV Long : Inert to Weak

    UV Short : Inert to Weak

    Pleochroism : 2 Colors

    Strength : [...]

  • Amber

    Refractive Index : 1.540 (+0.005 – 0.001)

    Optical Characteristic : SR, ADR

    Specific Gravity : 1.08 (+0.02 – 0.08)

    Formula : [C,H,O]

    Crystal System : Non-crystalline

    Variety/Species : All

    Species/Group : Amber

    Birefringence : None

    Dispersion : None

    Hardness : 2 to 2.5

    Toughness : Poor

    Ultrasonic : Never

    Steam : Never

    UV Long : Inert to strong

    UV Short : Weak

    Pleochroism : None

    Strength : N/A

    Pleochroism Colors : None

    Heat [...]