Sunstone

Sunstone
General
Categorymicrocline or oligoclase and orthoclase variety
Formula
(repeating unit)
(Ca,Na)((Al,Si)2Si2O8)
Crystal systemTriclinic
Identification
ColorColorless, orange, yellow, red, green, blue, brown and copper shiller
Crystal habitEuhedral crystals, granular
TwinningLamellar
Cleavage001
Mohs scale hardness6.0–6.5
DiaphaneityTransparent to translucent and opaque
Specific gravity2.64–2.66
Refractive index1.525–1.58

Sunstone is a microcline or oligoclase feldspar, which when viewed from certain directions exhibits a spangled appearance. It has been found in Southern Norway, Sweden, various United States localities and on some beaches along the midcoast of South Australia.