mineral

Polished Ocean Jasper cabochon

Ocean jasper: microcrystalline quartz (SiO₂), commonly mixed with chalcedony, feldspar, and iron/manganese oxides

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque white, green, gray, and brown orbicular pattern with a waxy to vitreous polish. It is cryptocrystalline, lacks visible cleavage, and has specific gravity near 2.6.

Identified August 16, 2026More mineral →

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At a glance

Common name: Polished Ocean Jasper cabochon
Scientific name: Ocean jasper: microcrystalline quartz (SiO₂), commonly mixed with chalcedony, feldspar, and iron/manganese oxides
Category: mineral
Identified: August 16, 2026
Method: Standard

AI Estimated Value

About $10–$40 for a small polished pendant blank; $40–$150+ for an attractive larger or finely patterned specimen.

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

Hardness about 6.5–7 Mohs; opaque white, green, gray, and brown orbicular pattern with a waxy to vitreous polish. It is cryptocrystalline, lacks visible cleavage, and has specific gravity near 2.6.

Formation & geological history

Formed when silica-rich fluids filled cavities and replaced volcanic rock, producing orbicular chalcedony/jasper; most collectible material formed in Oligocene–Miocene volcanic rocks of Madagascar. The pictured piece is cut and polished.

Uses & applications

Used for cabochons, beads, carvings, and decorative specimens; generally unsuitable for major construction because it occurs as lapidary material.

Geological facts

Its distinctive concentric “orb” patterns arise from alternating chalcedony, quartz, and mineral-rich layers. Ocean jasper is also marketed as orbicular jasper, though patterns and composition vary substantially.

Field identification & locations

Identify it by testing for quartz-like hardness, opaque orbicular spots, and a smooth polish; avoid confusing it with painted or dyed jasper. Classic sources are the remote northwest coast of Madagascar, especially near Marovato.