Sandstone Pebble
Arenite (primarily SiO2)
Rock Type: sedimentary

Physical Properties
Hardness: 6-7 on Mohs scale; Color: Tan, beige, or yellowish-brown; Luster: Dull/Earthy; Crystal Structure: Clastic (sand-sized grains); Cleavage: None (conchoidal fracture on grains); Specific Gravity: 2.2-2.8
Formation & Geological History
Formed through the accumulation and cementation of mineral particles or rock fragments (sand) in environments like riverbeds, deserts, or beaches. This specimen appears water-worn and rounded by fluvial or coastal transport.
Uses & Applications
Used primarily as construction aggregate, road base, and decorative landscaping gravel. In larger forms, sandstone is a major dimension stone for architecture.
Geological Facts
Sandstone comprises about 20-25% of all sedimentary rocks on Earth. It often acts as a massive reservoir for groundwater, oil, and natural gas due to its high porosity.
Field Identification & Locations
Identify in the field by its gritty, sandpaper-like feel and the visible presence of small, cemented sand grains. Common in riverbeds and ancient sedimentary basins worldwide.
Identified on: 4/26/2026
Mode: Standard