Quartz

Hardness of 7 on the Mohs scale, transparent to translucent with vitreous luster, hexagonal crystal system, and conchoidal fracture.

Forms in a wide range of geological environments, including igneous, metamorphic, and sedimentary rocks, through crystallization from silica-rich solutions or melts.

Widely used in electronics, oscillators, glassmaking, abrasives, and as a semi-precious gemstone in jewelry.

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

Easily identified by its high hardness (scratches glass), lack of cleavage, and distinct conchoidal fracture; found worldwide in almost all rock types.