sedimentary

Weathered gray rock fragment

Likely quartz-rich sandstone or weakly metamorphosed sandstone; exact identification is uncertain from the photograph

AI-generated identification · may be incorrect

Tan-gray, dull and granular, with irregular fracture and no visible crystals or cleavage; likely Mohs hardness about 6–7 if quartz-rich, with low-to-moderate density. The surface appears naturally weathered rather than polished.

Identified August 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably lithified sand deposited in an ancient sedimentary environment, then cemented by silica, calcite, or iron oxides; its geological age cannot be determined visually. It may also be a small piece of weathered concrete or pavement aggregate, though it appears natural.

Uses & applications

As a small fragment it has no practical industrial or jewelry value; sandstone is used widely as building stone, paving, and aggregate.

Geological facts

Quartz grains and subtle layering would support sandstone; a fizz with dilute hydrochloric acid would suggest calcite cement or limestone. A hand lens is useful for distinguishing grains from a uniform manufactured material.

Field identification & locations

Common in sedimentary terrains and construction fill worldwide; inspect for bedding, rounded sand grains, pores, and consistent natural texture. Estimated value: $0–$2 as an ordinary loose specimen; labeled or attractive sandstone samples may sell for about $5–$20.