Sunstone

Sunstone is a plagioclase feldspar, which when viewed from certain directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone.

Color Colorless, Yellow, Red, Green, Blue, and Copper Shiller
Mohs scale hardness 6.0 - 6.5
Specific gravity 2.55 - 2.76
Refractive index 1.560 - 1.572