Labradorite
Named after the town of Labrador Canada, where it was first discovered. Labradorite is a variety of the feldspar-group mineral orthoclase. During formation, orthoclase and albite separate into alternating layers. When light falls between these thin layers it is scattered producing the phenomenon called adularescence. Adularescence is the light that appears to billow across a gem. Other feldspar minerals can also show adularescence including moonstone and sanidine.
FACTS
MINERAL: Feldspar
COLOR: Gray,
REFRACTIVE INDEX: 1.518 to 1.526
BIREFRINGENCE: 0.05 to 0.008
SPECIFIC GRAVITY: 2.58
MOHS HARDNESS: 6.0 to 6.5
-Source GIA
