mineral

Polished black stone, likely hematite or black jasper

Hematite (Fe₂O₃) or opaque chalcedony/jasper (SiO₂); image-only identification is uncertain

AI-generated identification · may be incorrect

Smooth, highly polished, opaque black-gray surface with vitreous to submetallic luster; likely Mohs 5.5–6.5 (hematite ~5–6.5, jasper ~6.5–7). Crystal structure is not visible; hematite has trigonal symmetry, while jasper is microcrystalline quartz.

Identified August 16, 2026More mineral →

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At a glance

Common name: Polished black stone, likely hematite or black jasper
Scientific name: Hematite (Fe₂O₃) or opaque chalcedony/jasper (SiO₂); image-only identification is uncertain
Category: mineral
Identified: August 16, 2026
Method: Standard

AI Estimated Value

About $3–$20 for a common polished stone; $20–$75 if unusually large, attractive, or confirmed as a quality 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

Formation & geological history

Hematite forms through oxidation and hydrothermal or sedimentary processes; jasper forms when silica-rich fluids replace or cement volcanic/sedimentary material. Both occur in rocks ranging from Precambrian to modern geologic settings.

Uses & applications

Commonly sold as a tumbled stone, cabochon, worry stone, or ornamental object; hematite is also an important iron ore, while jasper is used for carvings and jewelry. Typical value is modest.

Geological facts

A streak test is useful: hematite leaves a distinctive reddish-brown streak, whereas jasper leaves little or no streak on unglazed porcelain. Strong attraction to a magnet would suggest magnetite rather than either likely candidate.

Field identification & locations

Common sources include iron-formation districts worldwide for hematite and volcanic or sedimentary terrains for jasper. The very smooth rounded shape indicates human polishing, not a naturally weathered pebble.