metamorphic

Quartz-veined river pebble

Quartz-bearing metamorphic rock, possibly silicified schist or altered volcanic rock

AI-generated identification · may be incorrect

Dark gray-brown, rounded and waterworn, with white-to-translucent quartz veins and rusty iron-oxide staining. Quartz is Mohs 7 with vitreous luster; the fine-grained host appears tougher and lacks obvious cleavage.

Identified September 5, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when silica-rich fluids filled fractures in an older rock, followed by weathering and stream abrasion; the host may be Paleozoic or younger, but age cannot be determined from the photograph. Common in quartz-vein-bearing mountain terrains and river gravels.

Uses & applications

Primarily a geological/landscaping or lapidary specimen; attractive pieces may be polished or used as decorative stone, but it has little industrial value at this size.

Geological facts

The rusty yellow-brown zones are limonite/goethite produced by oxidation of iron-bearing minerals. Its rounded shape indicates prolonged transport in a stream or gravel deposit.

Field identification & locations

Identify by its dense gray host, irregular white quartz seams, and iron staining; a glassy fracture and scratch resistance distinguish quartz from softer coatings. Exact locality and tests such as hardness, streak, and acid reaction are needed for precise identification.