Scoria
SCORIA (Lat. scoria, slag), in geology, a name applied to lava when moderately vesicular and having a structure like that of a clinker. Ejected masses of scoriaceous lava are often called " cinders," a term conveniently used for all lumps of vesicular lava (see VOLCANO).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)
