sedimentary

Yellow Jasper (Mookaite style)

Silicon Dioxide (SiO2) with Goethite/Hematite inclusions

Hardness: 6.5-7 (Mohs); Color: Mustard yellow, ochre, and earthy red; Luster: Dull to greasy (waxy when polished); Crystal Structure: Microcrystalline (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.6-2.9

Hardness: 6
Color: Mustard yellow, ochre, and earthy red
Luster: Dull to greasy (waxy when polished)

Identified March 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the petrification of radiolarian oozes and fine sedimentary deposits where silica-rich fluids permeate the ground, replacing organic or mineral matter. Most specimens date back to the Cretaceous period (approx. 66-145 million years ago).

Uses & applications

Commonly used for lapidary work (cabs, beads, carvings), ornamental stone displays, and metaphysical healing collections. It is also used as a gemstone in artisan jewelry.

Geological facts

Jasper is known as the 'supreme nurturer.' This specific yellow variety often contains 'ghosts' of ancient marine organisms. The name 'Jasper' is derived from the Greek word 'iaspis', meaning spotted stone.

Field identification & locations

Identify by its opaque nature, conchoidal (shell-like) fracture, and inability to be scratched by a steel knife. Commonly found in Western Australia (Mooka Creek), South Africa, and the Western United States. Look for smooth, waxy surfaces on broken edges.

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