Sunstone | |
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General | |
Category | microcline or oligoclase and orthoclase variety |
Formula (repeating unit) | (Ca,Na)((Al,Si)2Si2O8) |
Crystal system | Triclinic |
Identification | |
Color | Colorless, orange, yellow, red, green, blue, brown and copper shiller |
Crystal habit | Euhedral crystals, granular |
Twinning | Lamellar |
Cleavage | 001 |
Mohs scale hardness | 6.0–6.5 |
Diaphaneity | Transparent to translucent and opaque |
Specific gravity | 2.64–2.66 |
Refractive index | 1.525–1.58 |
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.