mineral
Polished/tumbled brecciated jasper (likely rainforest or ocean jasper)
Microcrystalline quartz (SiO₂), commonly mixed with chalcedony, iron oxides, and other silicates
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; opaque, multicolored brown, red, gray, cream, and green patches; waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The wet or polished surface intensifies its colors.
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Physical properties
Hardness about 6.5–7 Mohs; opaque, multicolored brown, red, gray, cream, and green patches; waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The wet or polished surface intensifies its colors.
Formation & geological history
Forms when silica-rich fluids replace or cement volcanic or sedimentary material, often producing brecciation and iron-oxide staining. The exact geological age and locality cannot be determined from the photograph; ocean jasper is chiefly associated with Miocene volcanic rocks of Madagascar.
Uses & applications
Used for cabochons, beads, carvings, polished display stones, and lapidary art; occasionally sold as decorative aggregate. It is generally a collectible ornamental material rather than a construction stone.
Geological facts
Jasper is a variety of opaque chalcedony, and its patterns commonly result from brecciation, mineral replacement, and iron staining. “Ocean jasper” is a trade name applied to orbicular or patterned jasper, not a single formally defined mineral species.
Field identification & locations
Identify it by its opaque silica-rich body, hardness, lack of cleavage, and red-brown iron staining; it should resist scratching by a steel blade. Common jasper occurs worldwide, while confirmed ocean jasper localities are concentrated in Madagascar; exact identification requires locality or testing.
