Definitions for "Scoria"
The recrement of metals in fusion, or the slag rejected after the reduction of metallic ores; dross.
Cellular slaggy lava; volcanic cinders.
It is a term for the irregular masses of lava which resembles clinker of slag; may be cellular (vesticular), dark-coloured and heavy.
the scum formed by oxidation at the surface of molten metals
bubble-filled stones ejected from a volcano