MIDWEST

Perlite is not a trade name but a generic term for naturally occurring siliceous volcanic rock. When heated to a suitable point it expands four to twenty times its original volume. Crude perlite rock contains 2 to 6 percent water which is the contributing factor of the expansion. At approximately 1600 ̊F the raw ore pops in a manner similar to popcorn. Perlite does not create by-products during processing; only the physical form is altered... Perlite: noun: (mineralogy) An amorphous volcanic glass formed by the hydration of obsidian. NOT a fertilizer.

Primary location: United States