sedimentary

Mookaite Jasper

Radiolarite (Silicified radiolarian chert), SiO2

Hardness: 6.5-7 (Mohs scale); Color: Variegated red, yellow, mustard, white, and purple; Luster: Vitreous to dull; Crystal structure: Trigonal/Microcrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.63-2.65

Hardness: 6
Color: Variegated red, yellow, mustard, white, and purple
Luster: Vitreous to dull

Identified May 31, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed as a sedimentary rock composed of the silicified remains of radiolaria (microscopic marine organisms) deposited in shallow seafloors. This specific variety is found in the Windalia Radiolarite formation, dating to the Cretaceous period (approx. 145-66 million years ago).

Uses & applications

Primarily used for lapidary work, jewelry (cabochons, beads), decorative carvings, and as a popular collectable specimen for metaphysical and geological interest.

Geological facts

The name 'Mookaite' is derived from Mooka Creek in Western Australia, which is the only place in the world where this specific colorful variety is found. The word 'Mooka' means 'running waters' in the local Aboriginal language.

Field identification & locations

Identify by its unique earthy color palette (mustard yellows and deep reds) and typical chert-like conchoidal fracture. It is exclusively found near the Kennedy Ranges in Western Australia. Collectors look for pieces with distinct color banding or 'pork belly' patterns.

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