mineral

Quartz (Milky or Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Creamy white to yellowish-tan due to iron oxide staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Creamy white to yellowish-tan due to iron oxide staining
Luster: Vitreous to greasy

Identified May 23, 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 in hydrothermal veins and pegmatites through the cooling of silica-rich magma or precipitation from hot aqueous solutions. This is one of the most common minerals in the Earth's crust.

Uses & applications

Used in glassmaking, ceramics, as an abrasive, in electronics (due to piezoelectric properties), and as a gemstone or decorative specimen.

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 on beaches.

Field identification & locations

Identify by its inability to be scratched by a steel knife (hardness) and the lack of cleavage planes. Found globally in all types of geological environments; commonly found in riverbeds and mountainous terrain.

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

Biotite Schist

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

metamorphic

Green Apatite on Albite

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

mineral