sedimentary

Rounded sandstone pebble

Quartz-rich sandstone, likely arkose or lithic sandstone

AI-generated identification · may be incorrect

Tan-brown, fine- to medium-grained, dull earthy luster with visibly cemented sand grains; hardness roughly 6–7 where quartz-rich, but it may scratch or crumble locally. No obvious cleavage; rounded by abrasion, with likely granular clastic texture and moderate porosity.

Identified September 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when sand-sized grains—mainly quartz with feldspar and rock fragments—were compacted and cemented, commonly by silica, calcite, or iron oxides. Its rounded shape indicates later stream, beach, or glacial transport; exact age and provenance cannot be determined from the image.

Uses & applications

Used widely as building and paving stone, aggregate, and occasionally as a decorative material; this small specimen is chiefly suitable for education or collecting.

Geological facts

The orange-brown color likely reflects iron-oxide staining. A fresh broken surface and acid test can help distinguish quartz cement from calcite cement.

Field identification & locations

Common in sedimentary basins and gravel beds worldwide. Look for visible sand grains, bedding or cement, and test hardness with a steel knife and glass; a hand lens is useful.