igneous
Polished orbicular gabbro (likely “leopard-skin” or larvikite-type material)
Gabbro, a coarse-grained mafic plutonic rock; chiefly plagioclase feldspar and pyroxene, with possible olivine/amphibole and iron oxides
AI-generated identification · may be incorrectDark green-black to gray matrix with irregular pale feldspar patches and glossy black mafic minerals; massive, granular, and polished. Hardness is approximately 6–7 Mohs; no obvious cleavage as a rock, with moderate-to-high density around 2.8–3.2 g/cm³.
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Physical properties
Dark green-black to gray matrix with irregular pale feldspar patches and glossy black mafic minerals; massive, granular, and polished. Hardness is approximately 6–7 Mohs; no obvious cleavage as a rock, with moderate-to-high density around 2.8–3.2 g/cm³.
Formation & geological history
Formed when mafic magma cooled slowly deep within Earth, allowing large crystals to develop; the precise geological age depends on its quarry source. The orbicular pattern reflects contrasting mineral-rich clots or zones during crystallization, rather than fossils.
Uses & applications
Used as a polished ornamental stone, carving material, paperweight, and collector specimen; rarely used for durable countertops or architectural stone. Value is mainly decorative and depends on pattern, polish, and size.
Geological facts
The specimen appears human-shaped and highly polished, possibly sold under a trade name such as “black-and-white gabbro” or “orbicular gabbro.” Similar commercial stones may be marketed inaccurately as jasper or granite.
Field identification & locations
Identify it by its coarse interlocking texture, high density, dark mafic minerals, and pale feldspar contrasts; a glassy polish does not indicate glass. Common sources include Norway, Madagascar, Finland, India, and other mafic-intrusion regions.
