Quartz Pebble

Physical Properties

Hardness: 7 (Mohs scale); Color: Translucent tan to creamy white; Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Formed through the crystallization of silica-rich hydrothermal fluids or within igneous rocks like granite. This specific specimen has been significantly rounded and smoothed by fluvial or marine erosion, often over thousands of years.

Uses & Applications

Quartz is used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel. River pebbles like this are frequently used in landscaping and aquarium decor.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krystallos', meaning ice. It is highly resistant to chemical weathering, which is why it often remains as pebbles after other minerals have eroded away.

Field Identification & Locations

Field identification: Hard enough to scratch glass, non-reactive with acid, and exhibits a lack of cleavage. Commonly found in riverbeds, beaches, and glacial deposits worldwide.

Identified on: 4/19/2026

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