Sandstone (with Liesegang rings or joints)

Physical Properties

Hardness: 6-7 (Mohs); Color: Reddish-brown, tan, or pink; Luster: Dull/Earthy; Structure: Clastic, granular; Features: Geometric box-work patterns caused by mineral precipitation or jointing.

Formation & Geological History

Formed through the lithification of wind-blown or water-borne sand. The geometric lines (often called boxwork or joints) are created by iron oxides concentrating along fractures or through fluid movement over millions of years.

Uses & Applications

Used primarily for construction, paving stones, and landscaping. Striking patterns like these make it popular for decorative specimens and garden architecture.

Geological Facts

The grid-like patterns often look man-made (mimicking ancient scripts or tiles), but are actually natural geometric fractures called joints that become stained with hematite or limonite.

Field Identification & Locations

Identify in the field by the visible sand grains and the orthogonal (90-degree) intersecting fracture lines. Commonly found in the Southwestern United States (Utah, Arizona) and sandstone formations globally.

Identified on: 4/22/2026

Mode: Standard