Sandstone (Micaceous)

Physical Properties

Hardness: 6-7 (individual grains); Color: Buff, tan, or light brown; Luster: Dull/Earthy with sparkling mica flakes; Texture: Granular/Clastic; Cleavage: None (structural bedding instead).

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. This specimen appears to contain mica flakes, suggesting a river or shallow marine depositional environment where fine sediments could settle.

Uses & Applications

Commonly used in construction as building stone, pavers, and decorative landscaping. Also serves as an important reservoir for ground water and petroleum.

Geological Facts

Sandstone is one of the most common types of sedimentary rock and makes up about 20% of all sedimentary rocks on Earth. The 'sparkle' often seen in samples like this one is caused by reflections from muscovite or biotite mica grains.

Field Identification & Locations

Identify in the field by its sandpaper-like feel and visible bedding planes. Found globally in deserts, river basins, and ocean coasts. For collectors, look for cross-bedding or fossil inclusions.

Identified on: 4/29/2026

Mode: Standard