Perlite - Medium, Fine and Coarse
Perlite is used in soil mixes.
Perlite is used (including in soilless mediums) to improve aeration and modify the soil substructure, keeping it loose, well-draining and defying compaction.
A premium mix of one part loam, one part peat moss, and one part perlite is optimum for container growing, enabling the pot to hold just enough water and oxygen.
Perlite is also great for rooting cuttings and fosters much stronger root formation than those grown in water alone. Take your cuttings and place them in a Ziploc bag of moistened perlite, about one-third full of perlite. Put the cut ends of the cuttings up to the node into the perlite and then fill the bag with air and seal it. Put the air-filled bag in indirect sunlight and check it after two or three weeks for root formation. The cuttings can be planted when the roots are ½ to 1 inch (1-3 cm.) long.
Other uses of perlite include masonry construction, cement and gypsum.