Quartz

Mohs hardness of 7, transparent to opaque, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage.

Formed in a wide range of geological environments, including igneous, metamorphic, and sedimentary rocks, often crystallizing from hydrothermal veins.

Used in electronics, watches, glassmaking, abrasives, and as a popular gemstone or mineral specimen for collectors.

Quartz is the second most abundant mineral in Earth's continental crust and exhibits piezoelectric properties, generating an electric charge under mechanical stress.

Identify by its hardness (scratches glass), lack of cleavage, and distinct conchoidal fracture. Found worldwide in nearly every geological setting.