Perlite comes from volcanic lava. I t is a kind of amorphous, glassiness volcano that contains crystalline water inside.
For expanded perlite has low density and low heat conductivity characters, it is widely used in construction and manufacturing fields, lightweight plasters and mortars, insulation, ceiling tiles and filter aids. In horticulture, it makes composts more open to air, while having good water-retention capacity. It is good carrier for soilless plant. Since last few years, expanded perlite is more and more popular in cryogenic use.