Quartz (Milky or White Quartz)

Physical Properties

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

Formation & Geological History

Forms in a wide variety of environments, most commonly from the cooling of magma or hydrothermal veins. It is found in igneous, metamorphic, and sedimentary rocks across all geological ages.

Uses & Applications

Used extensively in glass making, abrasive manufacturing, electronics (due to piezoelectric properties), construction as a component of granite/sandstone, and as a semi-precious gemstone.

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'. It is highly resistant to chemical and physical weathering.

Field Identification & Locations

Identify in the field by its hardness (it will easily scratch glass), its lack of cleavage, and its characteristic conchoidal (shell-like) fracture. Commonly found in riverbeds, mountains, and as 'white rocks' in landscaping.

Identified on: 4/13/2026

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