sedimentary
Chert (Mookaite style)
Silicon Dioxide (SiO2) with various inclusions
Hardness: 6.5-7 (Mohs scale), Color: Variegated mustard yellow, burgundy, and brown, Luster: Dull to waxy, Crystal Structure: Cryptocrystalline, Fracture: Conchoidal
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Variegated mustard yellow, burgundy, and brown, Luster: Dull to waxy, Crystal Structure: Cryptocrystalline, Fracture: Conchoidal
Formation & geological history
Formed from the skeletal remains of radiolaria (microscopic marine organisms) deposited in shallow seabed environments, later undergoing silicification. This specific coloration is characteristic of the Windalia Radiolarite in Western Australia.
Uses & applications
Primarily used as a lapidary material for jewelry, cabochons, and decorative carvings; historically used by indigenous people for stone tools.
Geological facts
The term 'Mookaite' comes from Mooka Creek in Western Australia. It is a silicified radiolarite that is highly sought after by collectors for its vibrant, clay-like appearance.
Field identification & locations
Identify by its waxy texture, shark-like conchoidal fractures, and distinct color bands. Often found in scree slopes or creek beds in specific Australian localities.
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