mineral

Milky Quartz (Tumbled/Water-worn)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to pale yellow/tan; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to pale yellow/tan
Luster: Vitreous to greasy

Identified March 21, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to pale yellow/tan; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen appears to be water-worn, indicating it was shaped by alluvial processes in a river or coastal environment over thousands of years.

Uses & applications

Used in the production of glass, ceramics, and electronics (due to piezoelectric properties). In this form, it is popular for landscaping, aquarium substrate, and as 'pocket stones' for crystal healing or beginners' rock collections.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of fluids or gases trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its waxy/greasy luster when rounded. It is found globally in almost all geological environments, particularly mountain streams and beaches.

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