sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide cement)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Tan, brown, or reddish due to iron oxidation; Luster: Dull/Earthy; Crystal Structure: Clastic (visible sand-sized grains); Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 (Mohs scale)
Color: Tan, brown, or reddish due to iron oxidation
Luster: Dull/Earthy

Identified February 17, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Tan, brown, or reddish due to iron oxidation; Luster: Dull/Earthy; Crystal Structure: Clastic (visible sand-sized grains); Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed by the accumulation and cementation of mineral particles or rock fragments (sand) over millions of years. This specimen appears water-worn (rounded), likely originating from a riverbed or coastal environment where it was smoothed by erosion.

Uses & applications

Commonly used as a construction material (dimension stone), in glass manufacturing, and as a reservoir rock in the petroleum industry. Smaller rounded pebbles are used in landscaping and decorative aquariums.

Geological facts

Sandstone is one of the most common sedimentary rocks on Earth, making up about 10-20% of all sedimentary rock. It often preserves fossils and ripple marks from ancient environments.

Field identification & locations

Identify by its 'sandpaper' feel and visible grains. It is commonly found in sedimentary basins, deserts, and riverbeds globally. Collectors look for unique colors or fossil inclusions.