Rock Identifier
Tumbled quartz-rich pebble (Microcrystalline quartz (SiO₂), possibly quartzite or chalcedony-bearing stone) — mineral
mineral

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly quartzite or chalcedony-bearing stone

AI-generated identification · may be incorrect

Hardness about 7 Mohs; gray to brown, dull-to-waxy luster, fine-grained massive texture, and no visible cleavage. The rounded shape and surface smoothing indicate natural water wear or tumbling.

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Physical properties

Hardness about 7 Mohs; gray to brown, dull-to-waxy luster, fine-grained massive texture, and no visible cleavage. The rounded shape and surface smoothing indicate natural water wear or tumbling.

Formation & geological history

Likely formed from silica-rich metamorphic or volcanic material, then weathered and rounded in a stream or beach environment; its exact geological age cannot be determined visually.

Uses & applications

Suitable as a pocket stone, craft/tumbled-stone material, or inexpensive decorative specimen; quartz-rich aggregate may also be used in construction.

Geological facts

Quartz commonly shows conchoidal fracture rather than cleavage and resists scratching by ordinary steel. The image does not show diagnostic crystal faces or distinctive color banding for a more specific identification.

Field identification & locations

Look for glassy/waxy surfaces, strong hardness, and lack of cleavage; a steel file should generally fail to scratch it, while quartz can scratch glass. Common worldwide in river gravels, beaches, quartz veins, and quartzite outcrops.