mineral

Milky Quartz with inclusions

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale); Color: White to grey with dark impurities; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to grey with dark impurities
Luster: Vitreous to greasy

Identified April 9, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to grey with dark impurities; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent of igneous rocks. It can be found in a wide variety of geological environments ranging from Precambrian to recent ages.

Uses & applications

Used in glassmaking, as an abrasive, in the electronic industry for its piezoelectric properties, and as decorative stone or gravel in landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudiness from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and common occurrence in veins. It is often the last mineral to weather away, found commonly as pebbles in stream beds.

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