mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

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

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous (glassy) to greasy

Identified April 7, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: 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 through hydrothermal activity in veins. It is found in igneous, metamorphic, and sedimentary environments globally, dating back billions of years.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction as an abrasive or aggregate, and semi-precious jewelry/lapidary arts.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which likely has Slavic roots meaning 'hard'.

Field identification & locations

Identify by its ability to scratch glass and steel, its lack of cleavage, and its characteristic greasy-white appearance. Often found as veins in granite or as pebbles in riverbeds.