mineral

Milk Quartz (Tumbled)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal (hexagonal system); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous (glassy) to greasy

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The white 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in geological environments ranging from billions of years old to relatively recent deposits.

Uses & applications

Used widely in lapidary work for tumbled stones and beads. Industrial uses include glassmaking, abrasives, and as a source of silica for silicon chips. Often used in home decor and by collectors of 'holistic' or metaphysical stones.

Geological facts

Milk quartz is the most common variety of crystalline quartz. While often overlooked for its rarer cousins like amethyst or citrine, it is the primary constituent of many white sand beaches and quartz veins found in mountain ranges.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), white color, and lack of cleavage planes. It is found globally, notably in the Appalachian Mountains, the Alps, and Brazil. Collectors should look for smoothness and consistent opacity without heavy staining.