mineral

Polished orbicular jasper (likely ocean jasper)

Silica-rich chalcedony/quartz aggregate with microcrystalline quartz, commonly containing feldspar and iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown-gray matrix with pale green-white orbicular or brecciated patterns and a waxy to dull luster. It is microcrystalline, lacks visible cleavage, and has conchoidal fracture; exact identification is limited by the photograph.

Identified August 15, 2026More mineral →

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At a glance

Common name: Polished orbicular jasper (likely ocean jasper)
Scientific name: Silica-rich chalcedony/quartz aggregate with microcrystalline quartz, commonly containing feldspar and iron-oxide inclusions
Category: mineral
Identified: August 15, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small tumbled piece; $30–$150+ for attractive, well-patterned cabochons or specimens.

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 volcanic fluids fill cavities or replace volcanic material, producing concentric orbicules and cemented patterns. Ocean jasper is chiefly associated with Miocene volcanic rocks of Madagascar, though similar jasper occurs worldwide.

Uses & applications

Used for cabochons, beads, carvings, polished stones, and lapidary collections; it has little industrial use beyond decorative silica material.

Geological facts

“Ocean jasper” is a trade name rather than a single formally defined mineral species. Its spherical patterns are caused by repeated mineral precipitation, replacement, and crystallization.

Field identification & locations

Look for opaque, patterned chalcedony with hardness near quartz, no cleavage, and a smooth polish; a streak test is usually white. Common jasper sources include Madagascar, Brazil, India, Mexico, and the United States.