mineral

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white with orange/brown iron staining
Luster: Vitreous to waxy

Identified March 28, 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 cooling igneous magma. This specific specimen appears to be a water-worn river pebble, likely hundreds of thousands to millions of years old, shaped by erosion in a high-energy aquatic environment.

Uses & applications

Used in electronics for piezoelectric properties, as an abrasive in sandblasting, in glassmaking, as a building aggregate, and as a common stone for tumbling and decorative landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krustallos' meaning ice, because ancient philosophers believed quartz was ice that had frozen so hard it would never melt.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel knives) and lack of cleavage planes. Pebbles like this are ubiquitous in riverbeds, glacial tills, and beaches globally; they are easy for novice collectors to find and polish.

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