mineral
Black polished stone or mineral fragment
Unidentified opaque dark mineral; possibilities include black tourmaline (schorl), obsidian, or hematite
AI-generated identification · may be incorrectAppears as a small, highly polished, opaque black-blue piece with vitreous to resinous luster; hardness cannot be determined reliably from the blurred image. Crystal structure, cleavage, and specific gravity are undetermined.
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Physical properties
Appears as a small, highly polished, opaque black-blue piece with vitreous to resinous luster; hardness cannot be determined reliably from the blurred image. Crystal structure, cleavage, and specific gravity are undetermined.
Formation & geological history
Likely a polished or tumbled geological material, but the image lacks enough detail to identify its composition, formation process, or geological age.
Uses & applications
Small polished specimens may be used in jewelry, cabochons, carvings, or mineral collections; value depends heavily on confirmed identity, size, and finish.
Geological facts
Black tourmaline commonly shows elongated striated crystals, obsidian has glassy conchoidal fracture, and hematite is unusually dense with a reddish-brown streak.
Field identification & locations
Use a sharper close-up plus tests for streak, hardness, magnetism, density, and translucency. A white streak test and side-view inspection would help distinguish hematite, obsidian, and tourmaline.
