metamorphic

Tumbled orbicular jasper (likely ocean jasper)

Silicified volcanic rock; mainly microcrystalline quartz (SiO₂) with iron oxides and other accessory minerals

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; polished brown, orange, black, and gray patterning with opaque coloration and a waxy-to-glassy luster. It is cryptocrystalline, with no visible cleavage and typically conchoidal fracture.

Identified September 4, 2026More metamorphic →

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At a glance

Common name: Tumbled orbicular jasper (likely ocean jasper)
Scientific name: Silicified volcanic rock; mainly microcrystalline quartz (SiO₂) with iron oxides and other accessory minerals
Category: metamorphic
Identified: September 4, 2026
Method: Standard

AI Estimated Value

Approximately $5–$25 for a small polished stone; $25–$75 if unusually patterned, large, or from a desirable locality.

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

Jasper forms when silica-rich fluids replace or cement volcanic ash and rock, commonly with iron-oxide staining; ocean jasper formed in volcanic rocks of Madagascar, largely during the late Oligocene–Miocene. Exact identification requires locality or testing.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and ornamental objects; it has modest lapidary value rather than gemstone-grade rarity.

Geological facts

Orbicular patterns result from concentric mineral growth or replacement around nuclei. The pictured elongated, polished specimen may also be another iron-rich jasper variety, since color alone cannot confirm ocean jasper.

Field identification & locations

Identify by its opaque multicolor silica-rich body, high polish, lack of cleavage, and ability to scratch glass; a steel file should not easily scratch it. Common sources include Madagascar, Australia, Brazil, India, and the western United States.