mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Mohs hardness: 7. Color: Opaque white to creamy. Luster: Vitreous to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7
Color: Opaque white to creamy
Luster: Vitreous to greasy

Identified July 6, 2026More mineral →

Explore Milky Quartz Pebble in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Mohs hardness: 7. Color: Opaque white to creamy. Luster: Vitreous to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Formation & geological history

Formed from hydrothermal solutions or the cooling of silica-rich magma; this specific piece has been rounded and smoothed by water erosion in a river or beach environment.

Uses & applications

Used in landscaping, as a source of silica for glassmaking, in abrasives, and commonly collected as a pocket stone or decorative item.

Geological facts

The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify by its white color, hardness (it will scratch glass), and lack of visible crystal faces due to water-worn rounding. Found globally in riverbeds, beaches, and gravel pits.