mineral

Quartz (Milky / Massive Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Milky white to light tan/greyish; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal to uneven fracture); Specific Gravity: 2.65

Hardness: 7 on the Mohs scale
Color: Milky white to light tan/greyish
Luster: Vitreous to greasy

Identified July 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes, crystallization from cooling magmas in igneous rocks, or precipitated in sedimentary and metamorphic environments. Found worldwide across various geological ages.

Uses & applications

Used in glassmaking, electronics (piezoelectric applications), abrasives, gemstone jewelry, and widely collected as ornamental mineral specimens.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is transparent, but microscopic gas/fluid inclusions give milky quartz its cloudy appearance.

Field identification & locations

Identified by its scratch hardness (scratches glass readily, cannot be scratched by steel nail), lack of cleavage, and vitreous to waxy luster. Commonly found in gravel beds, mountain streams, and quartz veins.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

sedimentary

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

mineral

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock