Clear Quartz On Feldspar rom Arkansas- Collectors Piece, GiftClear Quartz On Feldspar From Arkansas Collectors Piece, Gift Weight 600g Size 13. 5cm by 8cm Thickness 7cm Quartz is the most common and widely distributed mineral in the earths crust. It consists of oxygen and silicon (silicon dioxide). This crystal can be formed in numerous ways and occurs in most metamorphic and igneous rocks, especially in gneiss and granite. Since it resists weathering, you can find quartz in gravels and alluvial sands. Quartz