Sunstone

Sunstone is the name given to a gem variety of feldspar with a specific gravity 2.56 to 2.60. Monoclinic crystal system and a hardness 6-6.5 on the Mohs scale. The best quality pieces display a schiller effect, commonly with an orange/brown background colour, due to exsolved oriented small hematite and/or ilmenite crystals that give it an flash and sparkle.