sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2)

Hardness: 6.5-7 (Mohs); Color: Mixed shades of red, yellow, cream, and brown; Luster: Vitreous to greasy; Crystal structure: Microcrystalline/Cryptocrystalline; Specific Gravity: 2.65

Hardness: 6
Color: Mixed shades of red, yellow, cream, and brown
Luster: Vitreous to greasy

Identified June 3, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Mixed shades of red, yellow, cream, and brown; Luster: Vitreous to greasy; Crystal structure: Microcrystalline/Cryptocrystalline; Specific Gravity: 2.65

Formation & geological history

Mookaite is a fossiliferous sedimentary rock formed from the skeletal remains of radiaria (microscopic protozoa) that accumulated on the ocean floor and were later replaced by silica-rich fluids. It primarily dates to the Cretaceous era.

Uses & applications

Mainly used in lapidary arts for cabochons, beads, and carvings due to its vibrant colors and high polish. Also popular as a collector specimen and in metaphysical practices.

Geological facts

It is found exclusively in the Kennedy Ranges near Gascoyne Junction in Western Australia. The name 'Mookaite' comes from Mooka Creek, the locality where it is mined.

Field identification & locations

Identified by its distinctive earth-toned ribbons and glossy porcelain-like surface when polished. Look for it in the mookaite-bearing siltstone formations of Western Australia.