Perlite
Origin
From French perle ("pearl") + -ite
Noun
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, Well Tackled! Chapter 4, 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, …