Home Plant Products Distributers Contacts Blog A Showcase of our products by Application NORCAL Perlite Products NORLITE Perlite Products Horticulture Construction Industry Environmental Perlite Information Why Perlite Works How Perlite Works Physical Proprties Physical Characteristics Water Holding Water Holding Proprerty Perlite Garden Gardens In the Sky Perlite The Mineral For Healthy Plants Perlite Origin and Characteristics Perlite is a naturally-occurring siliceous rock. The distinguishing feature that sets perlite apart from other volcanic glasses is that when heated to a suitable point in its softening range, it expands from four to twenty times its original volume. While the crude rock may range from transparent light gray to glossy black: the color of expanded perlite ranges from snowy white to grayish white. Why Perlite Works Expanded perlite particles are clusters of minute, lightweight, insulating, glass bubbles. Its unique internal structure, together with a large exterior irregular surface composed of broken bubbles and surface openings provide for water and air holding capacity. Its internal structure resists thermal transmission, and crushed particles present a maze of microscopic pathways that can be used to filter and clean a wide array of liquids Norcal Metal Test Analysis The Test Analysts results on metallic content for our perlite Products Metal Test The Expansion Process This expansion is due to the presence of two to six percent combined water in the crude perlite rock. Expanded perlite can be manufactured to weigh as little as 2 pounds per cubic foot (32kg/m3), making it adaptable for numerous applications. Click on the picture above for s slide show of France expanding perlite This expansion process also creates one of perlite's most distinguishing characteristics: its white color. Because perlite is a form of natural glass, it is classified as chemically inert and has a pH of approximately 7All of our perlite is OMRI and CDFA Organic input material Certified. Expanded Perlite: The expanded product in various grades, with white snowy characteristic Certifications: All of our Expanded Perlite Products are OMRI and CFDA Organic input Material Certified. Certified Information presented with the curtesy of the Perlite Institute Safety Credit Application Certified (510) 232-7337 (510) 232-8127 fax 2605 Goodrick Ave. Richmond, CA 94801