Sand or volcanic glass which has been expanded by heat; perlite holds water and nutrients on its many irregular surfaces. Perlite can be used as a mineral soil amendment. Tobacco mosaic virus on tobacco. Related Articles: How to Grow Cannabis 231 - Blame the MediaAsk Me Anything: Women in CannabisUsing Perlite in Your Cannabis GrowPeat Alternatives: An Interview with Logan Leavitt of RainSoilMMAC - Los Angeles, CaliforniaRelated Terms:Term: MacronutrientsTerm: Mineral