Sandstone (Wonderstone)

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Tan, beige, reddish-brown, and gray bands; Luster: Dull to earthy; Crystal structure: Clastic (composed of mineral grains); Cleavage: None (conchoidal fracture); Specific gravity: 2.2–2.8.

Formation & Geological History

Formed from the lithification of sand-sized grains (mostly quartz) deposited in terrestrial or marine environments. The distinctive colorful bands (Liesegang rings) are produced by the rhythmic precipitation of iron oxides and hydroxides from groundwater within the porous rock.

Uses & Applications

Used extensively in construction for cladding and flooring, as landscaping decorative stone, and fine-grained varieties are used for carving or as 'wonderstone' specimens for collectors.

Geological Facts

The rhythmic bands, called Liesegang rings, were first described by chemist Raphael E. Liesegang. These patterns can often mimic natural landscapes, leading many to call these specimens 'Picture Sandstone'.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible bedding or banding. Common in arid environments like the Southwestern United States (Kanab, Utah) and Australia.

Identified on: 4/17/2026

Mode: Standard