igneous
Dark mafic rock, likely altered basalt or gabbro
Fine- to medium-grained mafic silicate rock; probable basaltic composition with plagioclase and pyroxene, possibly chloritized/serpentinized
AI-generated identification · may be incorrectBlack to dark green-gray matrix with mottled cream, tan, and rusty patches; dull to slightly crystalline luster, massive texture, no obvious cleavage. Estimated Mohs hardness 5–6; exact density and grain size are uncertain from the photograph.
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Physical properties
Black to dark green-gray matrix with mottled cream, tan, and rusty patches; dull to slightly crystalline luster, massive texture, no obvious cleavage. Estimated Mohs hardness 5–6; exact density and grain size are uncertain from the photograph.
Formation & geological history
Likely formed from basaltic magma, then weathered or hydrothermally altered; the pale and brown areas may be feldspar, carbonate, quartz, or alteration minerals. The specimen is probably a natural fragment or rounded/cut hand sample, but its geological age cannot be determined visually.
Uses & applications
Common basalt and gabbro are used as aggregate, roadstone, and building stone; attractive polished pieces may be sold as decorative stone. This small specimen has little commercial value unless testing reveals an unusual mineral or meteorite origin.
Geological facts
The granular, interlocking appearance and irregular pale mineral patches favor terrestrial mafic rock over a meteorite, though a magnet and streak test would help. The reported southwestern Iran locality is geologically compatible with widespread volcanic and ophiolitic rocks.
Field identification & locations
Test for a weak-to-strong magnetic response, glassy streak, and hardness; a fresh broken surface and 10× loupe examination would improve identification. Likely regional alternatives include altered basalt, gabbro, or serpentinite; an acid test can detect carbonate veins.
