Milky quartz

Typically white to translucent, with a glassy to waxy luster and uneven fracture; Mohs hardness 7, no cleavage, hexagonal crystal structure, and specific gravity about 2.65.

Forms when silica-rich fluids crystallize in veins, cavities, and igneous or metamorphic rocks; specimens may range from ancient Precambrian deposits to geologically recent veins.

Used for glass, ceramics, abrasives, countertops, and engineered stone; attractive pieces are collected, though this rough specimen has limited gem value.

Its cloudy appearance results from microscopic fluid inclusions, fractures, or dispersed minerals. Quartz is one of Earth’s most abundant and chemically resistant minerals.

Common worldwide, including Brazil, Madagascar, the United States, and Alpine regions. Identify it by its hardness—scratching ordinary glass—lack of cleavage, six-sided crystals when developed, and white translucent appearance.