mineral

Quartz (Milky or Iron-stained)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale), Color: White, tan, or yellowish due to iron staining. Luster: Vitreous to waxy. Crystal Structure: Hexagonal/Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific Gravity: 2.65.

Color: White, tan, or yellowish due to iron staining
Luster: Vitreous to waxy

Identified April 21, 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 from cooling silica-rich magma or from hydrothermal veins. This specimen likely weathered out of a quartz vein and has been rounded by environmental exposure.

Uses & applications

Used in glassmaking, abrasives, jewelry (as semi-precious stone), and as a structural component for electronics due to piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained varieties can transition into 'citrine' colorations if the iron content and heat history allow.

Field identification & locations

Identify in the field by its inability to be scratched by steel, its lack of cleavage, and the presence of conchoidal (glass-like) fractures. It is found globally in river beds, beaches, and mountain outcrops.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

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