mineral

Milky Quartz (or Iron-Stained Quartz)

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white with yellowish-brown iron oxidation staining
Luster: Vitreous to greasy

Identified April 10, 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 where silica-rich fluids cool in veins, or as a primary mineral in igneous and metamorphic rocks. This specimen likely formed in a hydrothermal vein and has been weathered at the surface, leading to the iron-oxide staining (rust colors).

Uses & applications

Used in glass manufacturing, as an abrasive, in electronics (piezoelectric properties), in construction as aggregate, and as a semi-precious gemstone or metaphysical specimen.

Geological facts

Quartz is the second most abundant mineral in the Earth's continental crust. Milky quartz gets its opaque white color from microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and waxy/vitreous luster. Common in mountainous regions, riverbeds, and as veins in surrounding rock. Tips for collectors: check for crystal faces in cavities (vugs).

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