mineral

Milky Quartz with Hematite/Limonite staining

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to pinkish-brown, Luster: Vitreous to greasy, Crystal Structure: Hexagonal/Trigonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Identified June 6, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White to pinkish-brown, Luster: Vitreous to greasy, Crystal Structure: Hexagonal/Trigonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed through hydrothermal processes in veins or from the cooling of silica-rich magma (pegmatites). It can be found in a wide variety of geological environments ranging from igneous to metamorphic terrains.

Uses & applications

Used in glass manufacturing, as an abrasive, in the electronics industry for its piezoelectric properties, and as decorative gravel or landscaping stone.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and translucent milky appearance. Commonly found in riverbeds, mountains, and as vein material in many host rocks.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic