mineral

Polished black tourmaline (likely), spherical carving

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; identification is tentative from the reflective, dark surface alone

AI-generated identification · may be incorrect

Opaque black, glassy-to-vitreous luster, and rounded polished surface; tourmaline is trigonal, Mohs hardness 7–7.5, with no obvious cleavage. A shiny reflection is not diagnostic—hematite, obsidian, and glass can look similar.

Identified October 8, 2026More mineral →

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At a glance

Common name: Polished black tourmaline (likely), spherical carving
Scientific name: Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; identification is tentative from the reflective, dark surface alone
Category: mineral
Identified: October 8, 2026
Method: Standard

AI Estimated Value

About $10–$60 for a small, common polished sphere; higher-quality material or larger specimens may cost more.

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

If schorl, it crystallized in boron-rich granitic pegmatites or related metamorphic rocks; tourmalines range widely in age. The image cannot establish the sphere’s material or geological age.

Uses & applications

Polished spheres are used for collecting and décor; tourmaline is also a gemstone and a source of boron-bearing mineral specimens.

Geological facts

Sri Lanka is well known for gem minerals, including tourmaline, but this photograph does not confirm a Sri Lankan origin or even tourmaline composition.

Field identification & locations

Check for natural growth striations or chips showing crystal texture; glass may show bubbles, while hematite is unusually dense. The reported Sri Lankan locality makes tourmaline plausible, but testing hardness, streak, and specific gravity—or gemological analysis—is needed.