mineral

Ferruginous Quartz (River Pebble)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Hardness: 7 (Mohs scale); Color: Tan and olive-green with brown/orange iron staining; Luster: Vitreous to waxy (when wet); Crystal structure: Hexagonal (trigonal habit); Cleavage: None (conchoidal fracture).

Hardness: 7 (Mohs scale)
Color: Tan and olive-green with brown/orange iron staining
Luster: Vitreous to waxy (when wet)

Identified April 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within metamorphic rocks, then eroded and rounded by stream or river action. Iron impurities (hematite or goethite) seeped into micro-fractures over time.

Uses & applications

Aesthetics, decorative landscaping, tumbled stones, and as a collector's specimen for hobbyists interested in stream-worn minerals.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specific piece is a 'river pebble,' meaning its smooth shape was sculpted by thousands of years of tumbling in water.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel knife) and its smooth, water-worn texture. Commonly found in riverbeds, glacial tills, and beaches worldwide.

Other mineral specimens

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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