sedimentary
Ocean Jasper
Orbicular Jasper (SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Polychromatic with white, green, grey, and black orbicular patterns; Luster: Vitreous to waxy when polished; Crystal Structure: Trigonal (Microcrystalline); Specific Gravity: 2.6-2.9
- Hardness
- 6
- Luster
- Vitreous to waxy when polished
Identified More sedimentary →
Explore Ocean Jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Polychromatic with white, green, grey, and black orbicular patterns; Luster: Vitreous to waxy when polished; Crystal Structure: Trigonal (Microcrystalline); Specific Gravity: 2.6-2.9
Formation & geological history
Formed as a result of rhythmic precipitation of silica around a nucleus during volcanic activity, typically found in late cretaceous deposits. This specific variety is mined only from the coast of Madagascar.
Uses & applications
Primarily used for ornamental purposes, lapidary art, crystal healing, and as a collector's specimen due to its unique patterns.
Geological facts
Ocean jasper is unique because it can only be harvested at low tide. This specific skull carving showcases the 'orbicular' or 'spherical' patterns characteristic of high-quality Madagascar jasper.
Field identification & locations
Identify by the distinctive circular 'eyes' or dots within the matrix. It is found along the shoreline of Madagascar. Collectors should look for vibrant contrast and well-defined circles.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary