Quartz (Milky/Common)

Physical Properties

Hardness: 7 (Mohs scale), Color: White to off-white, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & Geological History

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in all types of geological environments and can date back billions of years depending on the host rock formation.

Uses & Applications

Used in the manufacture of glass, electronics (piezoelectric properties), abrasives, and as a component in concrete and mortar. It is also collected by hobbyists.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often remains as pebbles or sand even after other minerals have eroded.

Field Identification & Locations

Identify by its hardness (it will scratch glass and steel) and lack of cleavage planes. Common in riverbeds, mountains, and desert sands globally.

Identified on: 5/15/2026

Mode: Standard