mineral

Quartz / Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified March 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in all geological ages and environments, particularly in igneous rocks like granite and metamorphic rocks like quartzite.

Uses & applications

Used widely in glass making, ceramics, and abrasives. Large, clear specimens are used in electronics (oscillators) and jewelry. Small Milky Quartz pebbles are often used in landscaping and as decorative 'river rocks'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The white 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass/steel), lack of cleavage, and waxy-to-glassy luster. It is commonly found in gravel pits, riverbeds, and as veins in mountain outcrops worldwide.