Quartz (Milky/Common Quartz)

Physical Properties

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

Formation & Geological History

Formed through the cooling of magma or by precipitation from hydrothermal veins. This specimen appears water-worn or weathered, commonly found in riverbeds or sedimentary deposits.

Uses & Applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), and as architectural stone or landscaping gravel.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which has Slavic origins meaning 'hard'.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass and steel) and lack of cleavage. Look for the characteristic conchoidal (shell-like) fracture patterns on broken surfaces.

Identified on: 5/4/2026

Mode: Standard