mineral

Polished ocean jasper / orbicular jasper (probable)

Silica-rich chalcedony (microcrystalline quartz, SiO₂) with iron oxides and altered volcanic inclusions

AI-generated identification · may be incorrect

Typically hardness 6.5–7 Mohs, opaque to slightly translucent, with a waxy to vitreous luster and gray, green, cream, brown, or reddish patterns. It has no obvious cleavage, conchoidal fracture, and specific gravity near 2.6; the wet appearance is enhanced by polishing.

Identified August 14, 2026More mineral →

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At a glance

Common name: Polished ocean jasper / orbicular jasper (probable)
Scientific name: Silica-rich chalcedony (microcrystalline quartz, SiO₂) with iron oxides and altered volcanic inclusions
Category: mineral
Identified: August 14, 2026
Method: Standard

AI Estimated Value

About $10–$40 for a palm-sized common polished piece; $50–$200+ for vivid, well-patterned, authenticated material.

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

Forms when silica-rich fluids fill cavities and fractures in volcanic rocks, commonly producing orbicular or brecciated patterns; Madagascar ocean jasper is chiefly Cretaceous volcanic material. The shown piece appears shaped and highly polished.

Uses & applications

Used for cabochons, carvings, eggs, spheres, palm stones, and ornamental objects; it is primarily a decorative collector material rather than an industrial stone.

Geological facts

“Ocean jasper” is a trade name, not a single strict mineral species. True orbicular material from Madagascar is collectible because many deposits are depleted or restricted.

Field identification & locations

Identify it by its dense polished surface, quartz-like hardness, lack of cleavage, and irregular orbicular or plume-like inclusions; common sources include Madagascar, Mexico, Australia, and the western United States. A steel file should not easily scratch it.