we sell Perlite Ore and rate type of Minerals. Perlite products are made from amorphous alumino-silicate rock, which has some very special properties: it contain water which expands into steam on heating.Perlite is a generic term for natural occuring siliceous rock. It is Distinguished from other volcanic glasses, when heated to a suitable point in its softening rane, It expands from four to twenty time its original volume.