metamorphic

Rounded metamorphic rock (likely gneiss or schist)

Foliated quartz–feldspar–mica rock; precise identification requires closer examination

AI-generated identification · may be incorrect

Gray-brown, coarse and unevenly foliated with a dull to subtly sparkly luster. Likely quartz, feldspar, and mica; hardness roughly 6–7 Mohs, with no obvious cleavage at specimen scale.

Identified October 14, 2026More metamorphic →

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Physical properties

Gray-brown, coarse and unevenly foliated with a dull to subtly sparkly luster. Likely quartz, feldspar, and mica; hardness roughly 6–7 Mohs, with no obvious cleavage at specimen scale.

Formation & geological history

Formed when pre-existing rock was altered by heat and pressure deep in Earth’s crust; its age cannot be determined from the image and may range widely.

Uses & applications

Commonly used as crushed aggregate or dimension stone; this rounded specimen is mainly suitable for collecting or display.

Geological facts

Its rounded shape and smoothed surface suggest transport and abrasion in a stream or other high-energy setting.

Field identification & locations

Look for aligned or wavy mineral bands and visible mica flakes to distinguish gneiss or schist; similar rocks occur in ancient mountain belts worldwide. The image does not show enough diagnostic detail for a confident species-level identification.