mineral

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Translucent white to greyish-brown. Luster: Vitreous (glassy) to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Translucent white to greyish-brown
Luster: Vitreous (glassy) to greasy

Identified March 22, 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 hydrothermal processes, typically as mineral-rich hot water cools in veins or cavities within igneous and metamorphic rocks. This specimen appears to be a massive crystal growth on a base of host rock (matrix).

Uses & applications

Quartz is used extensively in glassmaking, abrasives, and the electronics industry (due to piezoelectricity). Specimens like this are primarily used for educational purposes, amateur collections, or decorative display pieces.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which likely originated from West Slavic words meaning 'hard'. Pieces of quartz have been used as tools since the Stone Age.

Field identification & locations

Identify in the field by its hardness (it should easily scratch glass) and lack of cleavage (it breaks in curved, shell-like pieces). Commonly found globally in mountains, riverbeds, and sedimentary deposits. Collectors look for well-defined crystal faces and high transparency.

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