mineral

Quartz (Milky or Citrine-leaning)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Pale yellowish-white to clear/milky; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Pale yellowish-white to clear/milky
Luster: Vitreous (glassy)

Identified March 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed from cooling silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals on Earth and can be found in rocks from almost all geological eras, particularly in granite and pegmatites.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a semi-precious gemstone in jewelry when it has high clarity or color saturation.

Geological facts

Quartz is chemically and physically very resistant to weathering. When rocks erode, the quartz grains often remain to form beach sands. It is the defining mineral for level 7 on the Mohs scale of hardness.

Field identification & locations

Identify in the field by its hardness (it can scratch glass and steel) and its lack of cleavage (it breaks in curved, shell-like patterns). It is commonly found in gravel, riverbeds, and mountainous outcroppings worldwide.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

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

metamorphic

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock

Granite

Granite (Phaneritic intrusive igneous rock)

igneous