sedimentary

Moqui Marble (Shaman Stone)

Ironstone Concretion (Fe2O3 - Hematite/Goethite shell with Sandstone core)

Hardness: 5.0 - 5.5 on Mohs scale; Color: Dark brown to black outer shell with tan/cream sandy interior; Luster: Sub-metallic to earthy; Crystal structure: Amorphous/microcrystalline shell; Shape: Spherical to disc-like.

Hardness: 5
Luster: Sub-metallic to earthy

Identified March 7, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed by the precipitation of iron oxide minerals from groundwater flowing through permeable Navajo Sandstone. Most specimens are approximately 130 to 180 million years old (Jurassic period), though the concretions themselves formed much later in the Cenozoic era.

Uses & applications

Primarily used in metaphysical practices, as decorative curiosities, and for geological study. Occasionally used in jewelry as wire-wrapped pendants.

Geological facts

Moqui Marbles are terrestrial analogs to 'Blueberries' found on Mars by the Opportunity rover. The name 'Moqui' comes from the Hopi Tribe word for 'the dead', as legend says ancestral spirits play with the marbles at night.

Field identification & locations

Identify by their distinct round shape and heavy iron-rich 'shell' surrounding a softer sand core. They are most famously found in Utah, USA, particularly around the Grand Staircase-Escalante National Monument. Note: Collecting them in National Parks is strictly prohibited.

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Sandstone or Siltstone

Arenite (if sandstone)

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Sandstone

Arenite (primarily SiO2)

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Shale or Slaty Mudstone

Argillaceous sedimentary rock

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Chert Breccia

Brecciated Chert (Microcrystalline Silica)

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Sandstone (Quartz-rich)

Arenite (SiO2)

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Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

sedimentary