mineral

Tumbled quartz pebble (likely milky quartz or chalcedony)

Quartz, SiO₂; possibly microcrystalline quartz (chalcedony)

AI-generated identification · may be incorrect

Smooth, rounded, translucent tan-brown specimen with a waxy-to-glassy luster; quartz hardness is Mohs 7, with no cleavage and conchoidal fracture. Exact identification is limited by the image; the color may result from iron staining or surface treatment.

Identified August 24, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in igneous, metamorphic, and hydrothermal environments and is extremely common in sedimentary gravels; geological ages vary widely. This piece has been mechanically tumbled and polished by humans.

Uses & applications

Used as a lapidary material, ornament, craft stone, and inexpensive collector specimen; quartz is also important industrially in glass, electronics, and abrasives.

Geological facts

Quartz is one of Earth’s most abundant minerals and is usually identifiable by its hardness and lack of cleavage. A steel blade should not easily scratch it, while quartz can scratch ordinary glass.

Field identification & locations

Common worldwide in river gravels, veins, and weathered rock; inspect for consistent translucency, conchoidal fracture, and hardness. A gemological test or close-up view is needed to distinguish quartz from chalcedony, feldspar, or dyed glass.