Sunstone, also known as aventurine feldspar or heliolite, is a variety of the oligoclase feldspar group of minerals. It is commonly mined in India where the stone is a medium to dark orange in colour and gets its schiller (metallic glitter) from impurities of haematite and goethite. In the late 1990s reserves were discovered in Oregon, USA and this sunstone gets its schiller from copper inclusions. Our sunstone is untreated. Hardness: 6-6.5 (Mohs).