mineral

Quartz (Milky/Tan)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: tan to milky-white translucent, Luster: vitreous to greasy, Crystal structure: Trigonal (Hexagonal prism), Cleavage: none (conchoidal fracture), Specific Gravity: 2.65

Identified June 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed through crystallization of silica-rich hydrothermal fluids or as a primary component of cooling igneous rocks. Often found in hydrothermal veins and pegmatites.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectricity), ceramics, and as a raw material for construction and sand casting. Polished specimens are used in lapidary work.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage (it breaks in curved shards), and translucent appearance. Commonly found in riverbeds and gravel pits.