Quartz

Hardness of 7 on the Mohs scale, vitreous luster, transparent to translucent, and conchoidal fracture with no true cleavage.

Forms in igneous, metamorphic, and sedimentary environments through the cooling of magma or precipitation from silica-rich aqueous solutions.

Used extensively in electronics, glassmaking, abrasive materials, and as a semi-precious gemstone in jewelry.

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

Easily identified by its distinct hexagonal crystal habit and inability to be scratched by a steel knife. It is found worldwide in virtually all geological settings.