mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to translucent with orange/brown iron oxide staining; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Luster: Vitreous (glassy) to greasy

Identified March 24, 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 or within igneous pegmatites as magma cools. Quartz is found in almost every geological age and environment, from ancient metamorphic shields to modern sedimentary riverbeds.

Uses & applications

Used in the manufacturing of glass, electronics (oscillators), abrasives, and as a concrete aggregate. Highly common in lapidary work and collector circles as landscape rocks or beginner specimens.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The white color in 'milky' quartz is caused by microscopic fluid inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its ability to scratch glass and lack of cleavage (it breaks in irregular, curvy pieces). It is commonly found in veins cutting through other rocks. Collectors should look for quartz veins in mountain ranges or riverbeds.

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