sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2 with impurities)

Hardness: 6.5-7 on Mohs scale; Color: Earth tones like brick red, mustard yellow, cream, and brown; Luster: Vitreous to dull; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7.

Hardness: 6
Color: Earth tones like brick red, mustard yellow, cream, and brown
Luster: Vitreous to dull

Identified March 14, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the fossilized remains of radiolaria (microscopic marine organisms) whose skeletal remains were deposited in shallow sea beds. Over millions of years (Cretaceous period), these sediments were silicified by groundwater into a porcelain-like chert/jasper.

Uses & applications

Predominantly used as a lapidary material for jewelry (cabochons, beads), decorative carvings, and as a popular specimen for crystal healing and mineral collectors.

Geological facts

Mookaite is found only in one place in the world: the Mooka Creek area in the Kennedy Ranges of Western Australia. The name 'Mooka' is an Aboriginal word meaning 'running waters'.

Field identification & locations

Identify in the field by its distinct 'painterly' bands of yellow and red and its smooth, porcelain-like texture. It occurs as nodules or beds in weathered radiolarite. Collectors should look for vibrant, contrasting color patterns.

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