sedimentary

Weathered sandstone or quartzite cobble

Quartz-rich sandstone; possibly weakly metamorphosed quartzite (SiO₂-dominant)

AI-generated identification · may be incorrect

Pale tan, fine- to medium-grained, dull earthy luster, with visible weathering and possible thin bedding/foliation. Quartz-rich sandstone has Mohs hardness about 6–7; quartzite is typically 7, with no prominent cleavage and specific gravity near 2.6.

Identified August 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed from compacted and cemented quartz sand, probably Paleozoic or younger; if metamorphosed, heat and pressure recrystallized it into quartzite. The rounded shape reflects transport and prolonged weathering.

Uses & applications

Common sandstone is used for building stone, paving, aggregate, and landscaping; quartzite is used as durable facing stone, road aggregate, and decorative material. This ordinary weathered cobble has little commercial value.

Geological facts

The image does not show diagnostic crystals or fossils, so exact identification is uncertain from appearance alone. A streak, hardness, grain inspection, and dilute-acid test would help distinguish sandstone from carbonate rock.

Field identification & locations

Common in streambeds, glacial deposits, upland gravels, and weathered outcrops worldwide. Look for sand-sized quartz grains and bedding in sandstone; a sugary, interlocking quartz texture and very high durability indicate quartzite.