Rock Identifier
Weathered sandstone boulder (Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement) — sedimentary
sedimentary

Weathered sandstone boulder

Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement

AI-generated identification · may be incorrect

Typically Mohs hardness 6–7, tan to gray-brown, dull to slightly gritty, and composed of visible sand-sized grains; it may show bedding, pores, and iron staining. The photograph is low-resolution, so exact mineralogy and texture cannot be confirmed.

Identified More sedimentary
Explore Weathered sandstone boulder in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Typically Mohs hardness 6–7, tan to gray-brown, dull to slightly gritty, and composed of visible sand-sized grains; it may show bedding, pores, and iron staining. The photograph is low-resolution, so exact mineralogy and texture cannot be confirmed.

Formation & geological history

Formed when sand was deposited, compacted, and cemented in ancient rivers, beaches, dunes, or shallow seas; age cannot be determined from the image. Weathering has rounded the exposed surface and darkened portions with biological or mineral staining.

Uses & applications

Commonly used as building stone, paving, landscaping rock, aggregate, and occasionally sculpture material. This ordinary outdoor boulder has little jewelry or collector value.

Geological facts

Sandstone strength and color depend strongly on cement type: silica makes it durable, while clay or calcite cement makes it softer and more weatherable. The dark surface may be lichen, soil, or weathering rather than a distinct mineral.

Field identification & locations

Look for gritty texture, sand-sized grains, layered bedding, and scratching resistance greater than steel with quartz-rich varieties; acid testing can distinguish calcareous sandstone. Common worldwide, especially in sedimentary basins and glaciated areas.