Quartz

Hardness: 7 on Mohs scale, Color: White, clear, or milky, Luster: Vitreous to greasy, Crystal structure: Trigonal, Cleavage: None, Specific Gravity: 2.65

Formed in a wide range of environments including igneous, metamorphic, and sedimentary rocks, often crystallizing from silica-rich hydrothermal solutions or magmas.

Used in glassmaking, electronics, oscillators, abrasives, and gemstone carving.

Quartz is one of the most abundant minerals in the Earth's continental crust and exhibits piezoelectric properties, meaning it can generate an electric charge in response to applied mechanical stress.

Can be identified by its characteristic conchoidal fracture, high hardness (scratches glass), and lack of cleavage. Found worldwide.