Sandstone (Ferruginous)

Physical Properties

Hardness: 6-7 (Mohs); Color: Tan, reddish-brown, or orange due to iron oxide; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific Gravity: 2.2–2.8

Formation & Geological History

Formed through the accumulation and cementation of mineral particles or rock fragments (0.0625 to 2 mm size) in river, lake, or ocean environments. This specimen likely formed in an oxidizing environment where iron-rich water cemented the grains together.

Uses & Applications

Used primarily as a construction material, as a component for glass manufacturing (if high silica), in architectural stone facades, and as a decorative garden stone or abrasive.

Geological Facts

Sandstone represents about 20% of all sedimentary rocks on Earth. Its porosity makes it a critical reservoir for water (aquifers) and oil/natural gas.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and distinct layers or bedding planes. It is commonly found in desert environments, plateaus, and near coastal areas.

Identified on: 4/25/2026

Mode: Standard