sedimentary
Mookaite Jasper
Silicified Radiolarite (SiO2 with impurities)
Hardness: 6.5-7 on Mohs scale; Color: Yellow, mustard, ochre, maroon, and purple; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.63-2.65
- Hardness
- 6
- Color
- Yellow, mustard, ochre, maroon, and purple
- Luster
- Vitreous to dull
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Yellow, mustard, ochre, maroon, and purple; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.63-2.65
Formation & geological history
Formed through the silicification of skeletal remains of tiny marine organisms called radiolarians. These settled on the ocean floor and were later replaced by silica-rich groundwater. They are primarily from the Cretaceous period (about 66-145 million years ago).
Uses & applications
Commonly used in jewelry (cabochons and beads), decorative ornaments, and spiritual collecting. Its hardness makes it suitable for lapidary work and tumbled stones.
Geological facts
Mookaite is found exclusively in Western Australia at the Kennedy Range. It is named after Mooka Creek, where 'Mooka' is an Aboriginal word meaning 'running waters'.
Field identification & locations
Identify by its unique earthy color combinations and waxy/glossy finish when polished. In the field, look for porcelain-like fractured fragments in dry creek beds near the Kennedy Ranges of Australia.
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