Labradorite
(lab'-ra-dor-I-t')
18th c.; geo. labrador
Feldspar with opalescent reflects, originally found on labrador coast in Canada
Color
Semi-transparent to opaque white to dark gray
Chemical composition
Na(AlSi3O8)Ca(Al2Si2O8)
Hardness (Mohs scale)
6 - 6,5
Specific gravity
2,70 ±0,05
Refractive index
1,559 - 1,568
Optical character
Biaxial +