mineral

Hematite Nodules (Moqui Marbles style)

Iron Oxide (Fe2O3)

Hardness: 5.5-6.5; Color: metallic grey to black with reddish-brown streak; Luster: Metallic to earthy; Crystal Structure: Hexagonal; Specific Gravity: 5.26

Hardness: 5
Color: metallic grey to black with reddish-brown streak
Luster: Metallic to earthy

Identified May 1, 2026More mineral →

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Physical properties

Hardness: 5.5-6.5; Color: metallic grey to black with reddish-brown streak; Luster: Metallic to earthy; Crystal Structure: Hexagonal; Specific Gravity: 5.26

Formation & geological history

Formed by the precipitation of iron-rich minerals from groundwater flowing through permeable sedimentary rock, typically sandstone, often during the Jurassic period.

Uses & applications

Primary ore of iron, used in pigments (ochre), jewelry (beads), and as a popular specimen for mineral collectors.

Geological facts

Small rounded hematite or goethite concretions found in sandstone are often called 'blueberries' on Mars, providing evidence of past water presence on the red planet.

Field identification & locations

Identified by their distinctive round or botryoidal shape and heavy weight for their size; a streak test on unglazed porcelain will leave a characteristic rust-red mark.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral