Clear quartz clusters. Quartz is one of the abundant minerals in the Earth. Quartz chemical compound name is refers to as silicon dioxide, or silica,( SiO2), and having a specific crystalline form (hexagonal). Quartz is physically and chemically resistant to weathering. The name quartz is a German word of ancient derivation. Quartz can come in a variety of colors: clear, white ( milky Quartz), gray( Phantom Quartz), purple (Amethyst) , yellow( Citrine, Golden Healer), brown(Smoky), black, pink(Rose Quartz), green (Chlorite Quartz, Forest Quartz), red ( Strawberry, Fire Quartz). Size: ~ 1-2.5 inches *Picture may vary from piece to piece.