Sandstone (likely Calcareous or Quartz-rich)

Physical Properties

Hardness: 6-7 on Mohs scale (if quartz-based); Color: light grey to tan; Luster: dull/earthy; Crystal structure: granular clastic texture; Cleavage: none; Specific gravity: 2.2-2.8.

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments, typically in river, lake, or marine environments. This specimen shows a weathered clastic texture likely from a recent geological period.

Uses & Applications

Used primarily in construction for building stone, road base, and as a reservoir rock in the petroleum industry. Also used for decorative landscaping.

Geological Facts

Sandstone accounts for approximately 20% of all sedimentary rocks on Earth. It is porous enough to act as a significant aquifer for groundwater.

Field Identification & Locations

Identify in the field by its 'sandpaper' feel and visible grains. If it fizzes with cold dilute HCl, it is calcareous sandstone. Found globally in basins and coastal regions.

Identified on: 4/21/2026

Mode: Standard