Rock Identifier
Mookaite Jasper (Silicified Radiolarite (SiO2)) — sedimentary
sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Multi-colored (red, yellow, purple, burgundy, cream); Luster: Vitreous to greasy; Crystal Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.63-2.65

Hardness
6
Color
Multi-colored (red, yellow, purple, burgundy, cream)
Luster
Vitreous to greasy
Identified More sedimentary

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Multi-colored (red, yellow, purple, burgundy, cream); Luster: Vitreous to greasy; Crystal Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.63-2.65

Formation & geological history

Formed through the silicification of radiolarian ooze (microscopic sea organisms) during the Cretaceous period (approx. 66-144 million years ago) in shallow marine environments.

Uses & applications

Primarily used for lapidary work, jewelry (cabochons and beads), decorative carvings, and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Mookaite is found exclusively in Western Australia along the Mooka Creek. The name is derived from the Aboriginal word 'Mooka', meaning 'running waters'. It is geologically unique because it contains traces of the skeletal remains of tiny marine protists called radiolaria.

Field identification & locations

Identify by its distinctive earthy 'mustard and maroon' color palette and high polish. In the field, look for porcellanite-like texture in the Kennedy Ranges. It is often found as seams or nodules in weathered decomposing radiolarite shale.