Sandstone (likely Quartzose Sandstone)

Physical Properties

Hardness: 6-7 (on Mohs scale if quartz-rich); Color: Tan, brown, or grey with reddish oxidation patches; Luster: Dull/Earthy; Crystal structure: Clastic (granular texture); Cleavage: None (fractures across grains); 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 appears water-worn, suggesting it was transport by a river or stream (alluvial) before being deposited. Age varies widely by location but matches typical terrestrial sedimentary basins.

Uses & Applications

Commonly used as a construction material (dimension stone), in glass manufacturing if high-purity quartz, and as a reservoir rock for oil, gas, and groundwater.

Geological Facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. The famous red rocks of the Grand Canyon and Petra in Jordan are primarily composed of sandstone layers.

Field Identification & Locations

Identify in the field by its 'gritty' feel (like sandpaper) and visible sand grains. It is extremely common in desert environments and ancient riverbeds. For collectors, look for unique weathering patterns or fossils within the layers.

Identified on: 4/17/2026

Mode: Standard