Sandstone (Banded)

Physical Properties

Hardness: 6-7 (Mohs); Color: Tan and gray with distinct purple/pink banding; Luster: Dull/Earthy; Crystal structure: Granular; Cleavage: None (conchoidal fracture); Specific gravity: 2.2–2.8

Formation & Geological History

Formed through the accumulation and cementation of mineral particles or rock fragments, often in ancient riverbeds, deltas, or desert environments. The banding suggests varying mineral deposition or oxidation states during layering.

Uses & Applications

Commonly used in construction (tiles, pavers), landscaping, and as decorative river stones. High quartz versions are used for glass manufacturing.

Geological Facts

The distinct banding seen here is often the result of rhythmic deposition or chemical changes (like iron oxidation) in the groundwater that flowed through the rock after burial.

Field Identification & Locations

Identify in the field by its sand-like texture (gritty to the touch) and visible layering/bedding planes. Frequently found in riverbeds or coastal areas where it has been smoothed by water erosion.

Identified on: 4/20/2026

Mode: Standard