gemstone

Polished orbicular jasper (likely ocean jasper)

Silica-rich microcrystalline quartz/chalcedony, SiO₂; trade name “ocean jasper” is commonly applied to orbicular jasper from Madagascar

AI-generated identification · may be incorrect

Polished, rounded stone with green, cream, and dark concentric orbicular patterns and small cavities. Quartz-group hardness ~6.5–7 Mohs, vitreous to waxy luster; microcrystalline structure, no visible cleavage, specific gravity ~2.6.

Identified October 9, 2026More gemstone →

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At a glance

Common name: Polished orbicular jasper (likely ocean jasper)
Scientific name: Silica-rich microcrystalline quartz/chalcedony, SiO₂; trade name “ocean jasper” is commonly applied to orbicular jasper from Madagascar
Category: gemstone
Identified: October 9, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small polished stone; higher-quality, well-patterned pieces may cost more.

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

Silica-rich volcanic or hydrothermal material formed the patterned chalcedony; precise origin and age cannot be determined from the image. Genuine ocean jasper is known from Miocene volcanic rocks of Madagascar.

Uses & applications

Used for cabochons, beads, carvings, and decorative objects; this appears shaped and polished for jewelry or collecting.

Geological facts

The circular patterns are called orbicules; cavities may be natural vugs. The distinctive Madagascar ocean-jasper locality is now depleted or difficult to access.

Field identification & locations

Identify by its polished surface, opaque-to-translucent chalcedony, and repeated orbicular bands; similar jaspers occur worldwide. The photo alone cannot confirm the specific locality or trade identity.