mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous (glassy) to greasy

Identified March 7, 2026More mineral →

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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

Formed through the cooling of silica-rich magma or from hydrothermal veins. Milky quartz specifically gets its appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth. It is found in geological settings ranging from Precambrian to Cenozoic eras.

Uses & applications

Used in glassmaking, abrasives, and as a component in concrete. In jewelry, it is used for beads and cabochons. High-purity quartz is essential for the electronics industry (silicon chips) and watches (oscillators).

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz' and the Greek 'krustallos', meaning ice. It is piezoelectric, meaning it generates an electric charge when mechanical pressure is applied.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and waxy-to-glassy luster. It is ubiquitous globally and frequently found in riverbeds, mountain veins, and as a primary component of granite/sandstone.