sedimentary

Polished orbicular jasper (likely kambaba jasper)

Kambaba jasper; cryptocrystalline quartz/chalcedony with dark green and gray orbicular aggregates, commonly associated with altered volcanic material

AI-generated identification · may be incorrect

Mohs hardness about 6.5–7; dark green-gray, opaque, with pale gray orbicular or brecciated patches and a smooth polished surface; dull to waxy luster; no visible cleavage; specific gravity roughly 2.5–2.7.

Identified September 12, 2026More sedimentary →

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At a glance

Common name: Polished orbicular jasper (likely kambaba jasper)
Scientific name: Kambaba jasper; cryptocrystalline quartz/chalcedony with dark green and gray orbicular aggregates, commonly associated with altered volcanic material
Category: sedimentary
Identified: September 12, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small polished palm stone; $25–$100+ for unusually patterned larger pieces.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed from silica-rich, altered volcanic or sedimentary material later silicified and patterned by mineral aggregates; commonly Precambrian in age, though exact age depends on locality.

Uses & applications

Used for cabochons, beads, carvings, palm stones, and lapidary collectibles; generally not used as a construction stone.

Geological facts

Its rounded pale markings can resemble fossil or microbial textures, but many specimens sold as kambaba jasper are geologically variable and may be sold under trade names such as kabamba stone.

Field identification & locations

Identify by the opaque dark green body, rounded gray-green patches, and waxy polish; verify with a hardness or specific-gravity test because serpentine, rhyolite, and other jaspers can look similar. Commonly marketed from Madagascar and parts of Africa.