Quartz

Hardness of 7 on the Mohs scale, clear to yellowish-white or amber color, vitreous luster, hexagonal crystal system, conchoidal fracture, specific gravity of 2.65

Forms in a wide variety of geological environments, commonly crystallizing from silica-rich hydrothermal veins, pegmatites, and as a primary constituent of igneous, metamorphic, and sedimentary rocks.

Used in electronics, oscillators, glassmaking, abrasives, and as a semi-precious gemstone or mineral specimen for collectors.

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 mechanical stress.

Easily identified by its characteristic hardness of 7 (scratches glass), lack of cleavage, and conchoidal fracture. Found worldwide in virtually every geological setting.