sedimentary

Ironstone Concretion (Moqui Marble)

Iron Oxide Concretion (Goethite and Hematite around a Sandstone core)

AI-generated identification · may be incorrect

Hardness: 5-5.5 (outer shell); Color: Brown, tan, or dark rusty orange; Luster: Dull/Earthy; Structure: Spheroidal/Concretionary; Cleavage: None

Hardness: 5-5
Color: Brown, tan, or dark rusty orange
Luster: Dull/Earthy

Identified April 1, 2026More sedimentary →

Explore Ironstone Concretion (Moqui Marble) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 5-5.5 (outer shell); Color: Brown, tan, or dark rusty orange; Luster: Dull/Earthy; Structure: Spheroidal/Concretionary; Cleavage: None

Formation & geological history

Formed by the precipitation of iron oxide minerals from groundwater flowing through porous sandstone, typically within the last few million years in Jurrasic-aged formations.

Uses & applications

Predominantly used as decorative collector specimens, metaphysical 'healing stones', and small landscaping accents.

Geological facts

Also known as Moqui Marbles, Shaman Stones, or Navajo Cherries. They often have a 'rattle' effect if the inner sandstone core becomes loose from the iron shell.

Field identification & locations

Identify by their perfectly round to disc-like shape, high weight for their size, and rough, weathered exterior surface. Commonly found in the Navajo Sandstone of the Southwest US.