mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

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

Identified February 28, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Often crystallizes from cooling magma or hydrothermal veins. It is found in geological formations ranging from the Archean era to the present.

Uses & applications

Used in glassmaking, abrasives, electronic oscillators (piezoelectricity), building materials, and as a semi-precious gemstone in jewelry and carvings.

Geological facts

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

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7) and its lack of cleavage (it breaks in curved, shell-like patterns). It is common worldwide, particularly in pegmatites and riverbeds.