sedimentary

Quartz Pebble (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale); Color: Creamy white to pale yellow; Luster: Waxy to vitreous; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Creamy white to pale yellow
Luster: Waxy to vitreous

Identified April 26, 2026More sedimentary →

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Physical properties

Hardness: 7 (Mohs scale); Color: Creamy white to pale yellow; Luster: Waxy to vitreous; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the precipitation of silica in sedimentary environments or as nodules in limestone/chalk. This specimen appears water-worn and smoothed, likely from a riverbed or coastal environment.

Uses & applications

Common varieties are used in landscaping, as abrasives, and in the manufacturing of glass and ceramics. Polished stones are used in folk jewelry and as 'pocket stones'.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. Microcrystalline varieties like this have been used since the Stone Age to create tools because of their hardness and predictable fracture patterns.

Field identification & locations

Identify by its ability to scratch glass and its smooth, waxy texture. Commonly found in gravel pits, beaches, and creek beds globally. For collectors, it is a basic foundational specimen.