sedimentary

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale), Color: Brownish-red to tan, Luster: Dull/Earthy, structure: Clastic (fine-grained sand), Cleavage: None/Irregular fracture, Specific Gravity: 2.2-2.8

Identified May 27, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale), Color: Brownish-red to tan, Luster: Dull/Earthy, structure: Clastic (fine-grained sand), Cleavage: None/Irregular fracture, Specific Gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. This specimen shows signs of iron oxide (hematite/limonite) cementation which gives it the brown color, likely rounded by water erosion in a fluvial or beach environment.

Uses & applications

Used in construction, as a building material, for paving stones, and sometimes in glass manufacturing if pure enough. This specific pebble size is common in landscaping gravel.

Geological facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. The layers within sandstone can often record ancient environments like deserts, rivers, or oceans through a process called cross-bedding.

Field identification & locations

Identify in the field by its gritty 'sandpaper' feel and visible small grains. Often found in riverbeds, canyons, and coastal areas. Collectors look for unique banding or fossil inclusions.