Sandstone (likely Arkosic or Quartzose)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Yellowish-tan/buff with grey specks; Luster: Dull/Earthy; Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2–2.8

Formation & Geological History

Formed through the accumulation and lithification of sand-sized mineral particles or rock fragments. This specimen appears weathered and stained by iron oxides, typical of terrestrial or shallow marine depositional environments from various geological eras.

Uses & Applications

Used primarily as construction material, road base, or aggregate. Highly weathered pieces are sometimes used in landscaping or as decorative stones.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. It is a major reservoir for water (aquifers) and oil/gas due to its high porosity.

Field Identification & Locations

Identify in the field by its gritty 'sandpaper' feel; it will often crumble slightly when rubbed. Commonly found in desert environments, river beds, and coastal areas. Collectors look for unique banding (Liesegang rings) or fossils within the layers.

Identified on: 4/16/2026

Mode: Standard