mineral

Quartz (Iron-stained Quartz Pebble)

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, waxy to vitreous luster, translucent to sub-translucent clarity, pinkish-tan to reddish-brown coloration from micro-inclusions of iron oxides, hexagonal crystal structure, conchoidal fracture.

Identified July 27, 2026More mineral →

Explore Quartz (Iron-stained 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

Formation & geological history

Formed through hydrothermal precipitation or cooling of silica-rich magma in pegmatites and veins. Water-worn into a rounded pebble through mechanical weathering and stream or beach erosion over thousands to millions of years.

Uses & applications

Commonly collected as river rocks or tumbled stones, used in decorative landscaping, lapidary art, and industrially as a source of silica.

Geological facts

Quartz is one of the most abundant minerals in Earth's continental crust. Iron oxide staining often gives quartz a warm reddish, pink, or rusty orange hue, which can reside either on the surface or within tiny internal fractures.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass easily, cannot be scratched by a steel knife), lack of cleavage, conchoidal fracture pattern, and rounded river-worn morphology. Found abundantly worldwide in stream beds, beaches, and gravel deposits.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Limonite / Goethite (Iron Ore Mineral nodule)

FeO(OH)·nH2O / FeO(OH)

mineral

Schist

Metamorphic

Septarian Pebble

Septarian nodule / Concretion

sedimentary

Potassium Feldspar (Orthoclase)

Orthoclase (KAlSi3O8)

mineral

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

sedimentary