igneous
Red Scoria (Volcanic Cinder)
Scoria (Extrusive Mafic Igneous Rock)
Hardness around 5-6, reddish-brown to dark red color due to iron oxidation, earthy to dull luster, highly vesicular (full of cavities), lightweight, fine-grained groundmass.
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Physical properties
Hardness around 5-6, reddish-brown to dark red color due to iron oxidation, earthy to dull luster, highly vesicular (full of cavities), lightweight, fine-grained groundmass.
Formation & geological history
Formed during explosive volcanic eruptions when gas-rich basaltic or andesitic lava cools rapidly, trapping expanding gas bubbles inside as solidifying rock. Red coloration develops due to oxidation of iron minerals during hot eruption.
Uses & applications
Widely used in landscaping, drainage, high-temperature insulation, lightweight aggregate in concrete, gas grill lava rocks, and decorative gardening.
Geological facts
Scoria is similar to pumice, but it is denser and sinks in water because its vesicle walls are thicker and composed of basaltic lava rather than felsic rhyolite.
Field identification & locations
Identified by its deep red color, rough, sponge-like vesicular texture, and relatively light weight. Found abundantly near volcanic cones, cinder cones, and active or extinct volcanic fields globally.
