mineral

Quartz (Milky or Rough Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: White to translucent/clear. Luster: Vitreous (glassy) to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: Poor/None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: White to translucent/clear
Luster: Vitreous (glassy) to greasy

Identified January 26, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in all geological ages and forms in igneous, metamorphic, and sedimentary environments. This specific specimen appears to be a massive variety formed in a vein.

Uses & applications

Extensively used in glass making, electronics (due to piezoelectric properties), abrasives, construction as a component of concrete, and as a semi-precious gemstone in jewelry or for decorative collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to both chemical and physical weathering, which is why it often remains as sand after other rocks have eroded away.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (it will scratch glass instead) and its lack of cleavage planes. It is found globally, notably in pegmatites and mountain ranges. Collectors look for the absence of bubbles (differentiating it from glass) and its signature conchoidal fracture which looks like curved glass breaks.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

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

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral