mineral

Quartz Pebble (with Iron Inclusions)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to yellowish-tan with reddish iron-oxide staining; Luster: Vitreous to waxy (when weathered); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous to waxy (when weathered)

Identified July 6, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in a wide variety of environments, most commonly from cooling magma in igneous rocks or through hydrothermal activity in veins. This specific specimen appears to be a river-worn or glacially-transported pebble, rounded by mechanical erosion over thousands to millions of years.

Uses & applications

Quartz is used in glassmaking, abrasives, and as a component in construction materials like concrete. Massive or rounded specimens are often collected as river stones or used for lapidary tumbling.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its yellow or reddish-brown coloration is often due to 'iron staining' where hematite or limonite has leached into the surface micro-fractures of the stone.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass but cannot be scratched by a steel knife) and its lack of cleavage. It is found globally in riverbeds, beaches, and mountain trails. Collectors often look for these to cut or polish into 'worry stones'.

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