Archive for the Orthoclase Feldspar Category

Moonstone

Refractive Index : 1.526 – 1.518 (+0.010 – 0.010)

Optical Characteristic : DR, biaxial negative

Specific Gravity : 2.58 (+0.03 – 0.03)

Formula : KAISi3O8

Crystal System : Monoclinic

Variety/Species : Orthoclase feldspar

Species/Group : Feldspar group

Birefringence : 0.005 to 0.008

Dispersion : 0.012

Hardness : 6 to 6.5

Toughness : Poor

Ultrasonic : Never

Steam : Never

UV Long : Inert to weak

UV Short : Inert [...]