scoria Synonyms

dross slag sinter sediment scum scobs block lava rubblestone rubble refuse recrement porphyry soot sprue ballast stone volcano matter Cinders abyssal rock grounds volcanic rock bedrock dregs waste trash tachylyte pahoehoe obsidian calx breccia brash brand bitumen basalt ashes ash anthracite alluvium carbon charcoal cinder magma lees lava impurity ember culm coulee coom coal clinker