perlite (plural perlites)
- (mineralogy) An amorphous volcanic glass formed by the hydration of obsidian.
- The lightweight insulating material and aggregate resulting from expanding perlite glass by heat.
1928, Lawrence R. Bourne, chapter 4, in Well Tackled!:
- Technical terms like ferrite, perlite, graphite, and hardenite were bandied to and fro, and when Paget glibly brought out such a rare exotic as ferro-molybdenum, Benson forgot that he was a master ship-builder, […]
perlite f (plural perliti)
- (mineralogy) perlite