Sandstone (likely Quartzose Sandstone)

Physical Properties

Hardness: 6-7 (Mohs scale for individual grains); Color: Tan, beige, with reddish-pink iron oxide staining; Luster: Dull/Earthy; Crystal structure: Clastic (grainy); Cleavage: None (breaks across grains); Specific Gravity: 2.0-2.6

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. This specimen appears to be a clastic sedimentary rock formed in high-energy environments like riverbeds or shallow seas. Its rounded shape suggests significant transport by water.

Uses & Applications

Commonly used in construction as a building material, aggregate for concrete, and for decorative masonry. Pure quartz sandstone is also used in glass manufacturing.

Geological Facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. The reddish tints seen in this specimen are usually caused by trace amounts of hematite or limonite (iron oxides).

Field Identification & Locations

Identify by its gritty, 'sandpaper' feel. Look for small, visible mineral grains. It is commonly found in sedimentary basins, river valleys, and coastal regions globally. Collectors should look for bedding planes or fossils occasionally trapped within.

Identified on: 4/25/2026

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