a variety of obsidian consisting of masses of small pearly globules: used as a filler, insulator, and soil conditioner
Derived forms
perlitic or pearlitic (pɜːˈlɪtɪk)
adjective
Word origin
C19: from French, from perlepearl1
perlite in American English
(ˈpɜrˌlaɪt)
noun
1. Geology
a greenish volcanic glass, similar to obsidian, with a pearly luster and multiple,minute concentric cracks, used as insulation and in making concrete, plaster, etc.