mineral

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Opaque white to creamy tan due to microscopic fluid inclusions. Luster: Vitreous to greasy. Crystal Structure: Trigonal (hexagonal prisms). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Luster: Vitreous to greasy

Identified April 13, 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 silica-rich hydrothermal veins or in igneous pegmatites. This specific specimen has been physically rounded and smoothed by water transport in a river, stream, or beach environment, often over thousands of years.

Uses & applications

Used as abrasive material, in glassmaking, and as decorative landscaping stone. In metaphysical circles, it is used for 'healing' or meditation. Pure varieties are used in electronics for piezoelectric properties.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Its white color is caused by tiny bubbles of gas or liquid trapped during the crystal's growth, which scatter light like the water droplets in a cloud.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), white color, and lack of cleavage. This rounded shape is a classic 'river rock' indicator. Found globally in almost every geological setting.

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