sedimentary

Mookaite Jasper

Silicified radiolarite (SiO2)

Hardness: 6.5-7 (Mohs); Color: Mixed shades of burgundy, cream, mustard yellow, and white; Luster: Vitreous to greasy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7

Hardness: 6
Color: Mixed shades of burgundy, cream, mustard yellow, and white
Luster: Vitreous to greasy

Identified March 23, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the silicification of skeletal remains of radiolaria (tiny marine organisms) that settled on the ocean floor during the Cretaceous period (approx. 145-66 million years ago). Subsurface groundwater high in silica replaced the calcium carbonate deposits.

Uses & applications

Primarily used as a gemstone for jewelry (cabochons, beads), decorative carvings, and as a popular collector's mineral due to its unique patterns.

Geological facts

Mookaite is named after Mooka Creek in Western Australia, which is the only place in the world where it is mined. It is technically more of a porcelanite or radiolarite than a true Jasper.

Field identification & locations

Identify by its distinct 'earth-tone' color banding and very high polish. In the field, look for brittle, multicolored sedimentary deposits near Mooka Creek, Australia. Collectors should look for vibrant, contrasting color zones.