metamorphic

Water-worn quartzite pebble

Quartzite, composed predominantly of quartz (SiO₂)

AI-generated identification · may be incorrect

Pale gray-blue with cream weathering patches and a dull to slightly waxy surface; quartz has Mohs hardness 7 and a trigonal crystal structure. The image shows a rounded, fine-grained pebble; cleavage is absent or indistinct.

Identified October 14, 2026More metamorphic →

Explore Water-worn quartzite pebble in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed when quartz-rich sandstone was metamorphosed and recrystallized under heat and pressure, then eroded and rounded by water. Its precise age and source cannot be determined from the photograph.

Uses & applications

Primarily a collectible or decorative pebble; quartzite is also used as crushed stone, paving, and building material.

Geological facts

Quartzite can resemble marble, but it is harder and typically does not react with dilute acid. Its interlocking quartz grains make it highly resistant to weathering.

Field identification & locations

Look for a hard, quartz-rich rock that tends to fracture through grains rather than around them; it commonly occurs in river and beach gravels near quartzite-bearing terrain. The specimen’s exact identification would require closer examination.