sedimentary

Sandstone (Cross-bedded Drill Core)

Clastic Sedimentary Rock (primarily SiO2)

Hardness: 6-7 (Mohs); Color: Grey to buff with darker laminations; Luster: Dull/Earthy; Structure: Clastic with visible cross-bedding; Cleavage: None (grains are cemented); Specific Gravity: 2.2–2.8

Hardness: 6-7 (Mohs)
Color: Grey to buff with darker laminations
Luster: Dull/Earthy

Identified March 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of sand-sized mineral particles or rock fragments. The visible 'cross-bedding' indicates deposition in a high-energy environment like a river channel or wind-blown dune. Geological age varies by location, often Paleozoic to Cenozoic.

Uses & applications

Used extensively in construction as dimension stone, road base, and as a reservoir rock for oil and natural gas. In engineering, drill cores like this are used to study sub-surface geology and porosity.

Geological facts

The curved lines visible in the core are 'cross-beds,' which are fossilized remnants of old ripple marks or underwater dunes. Geologists use these patterns to determine 'up' in a rock sequence if the layers have been overturned.

Field identification & locations

Identify in the field by its gritty texture (feels like sandpaper) and visible layers. High concentrations can be found in the Colorado Plateau (USA) and large basins worldwide. Look for consistent grain size and bedding planes.

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