igneous
Weathered iron-rich volcanic rock (probable basalt/scoria)
Basaltic volcanic rock; mainly plagioclase feldspar, pyroxene, and iron oxides
AI-generated identification · may be incorrectDark reddish-brown to gray, dull and fine-grained with rusty iron-oxide staining; likely Mohs 5–6, nonmetallic luster, massive texture, and no obvious cleavage. The irregular surface may reflect weathering or vesicles partly filled with alteration minerals.
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Physical properties
Dark reddish-brown to gray, dull and fine-grained with rusty iron-oxide staining; likely Mohs 5–6, nonmetallic luster, massive texture, and no obvious cleavage. The irregular surface may reflect weathering or vesicles partly filled with alteration minerals.
Formation & geological history
Formed when mafic lava cooled rapidly at or near Earth’s surface, likely in the Cenozoic or younger; its red coloration developed through oxidation during weathering. Exact age and identification require petrographic or chemical testing.
Uses & applications
Generally used as crushed aggregate, road base, riprap, and landscaping stone; this specimen has modest value as a geological sample rather than as jewelry material.
Geological facts
Iron oxidation can produce hematite- or goethite-rich red zones, while dark portions retain the original basaltic minerals. Its rough, dense appearance is more consistent with weathered basalt than with a metal-bearing meteorite.
Field identification & locations
Common in volcanic regions, including Hawaii, Iceland, the Pacific Northwest, India, and oceanic crust. Check for a fine crystalline groundmass, hardness greater than glass, lack of metallic flecks, and weak or absent magnetism; a streak, magnet test, and thin section would improve identification.
