mineral

Likely raw black tourmaline or dark amphibole fragment

Possibly schorl, NaFe3Al6(BO3)3Si6O18(OH)4; identification is uncertain from the image

AI-generated identification · may be incorrect

Small, opaque black fragment with vitreous-to-submetallic luster and uneven fracture; tourmaline hardness is 7–7.5 Mohs, while amphibole is about 5–6. It appears granular or prismatic rather than clearly crystalline.

Identified September 20, 2026More mineral →

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At a glance

Common name: Likely raw black tourmaline or dark amphibole fragment
Scientific name: Possibly schorl, NaFe3Al6(BO3)3Si6O18(OH)4; identification is uncertain from the image
Category: mineral
Identified: September 20, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an unidentified fragment; $5–$50 for a recognizable small schorl specimen, depending on crystal quality and provenance.

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 formed in boron-rich granite pegmatites or hydrothermal veins during late-stage magma crystallization; amphibole would typically form in igneous or metamorphic rocks. Exact age and origin require testing or locality information.

Uses & applications

Common tourmaline is used mainly as a collector mineral and occasionally in jewelry; dark fragments have little industrial value. Amphibole fragments are generally ornamental or specimen material.

Geological facts

Black tourmaline commonly shows lengthwise striations and triangular cross-sections, whereas amphibole tends to form elongated crystals with two cleavage directions.

Field identification & locations

Check for longitudinal striations, prismatic geometry, and electrical attraction when heated or rubbed; a streak, hardness, specific gravity, and locality test would improve identification. Common sources include Brazil, Afghanistan, Pakistan, Madagascar, and the United States.