The word can be used synonymously with "volcanic ash." It's mined from volcanic ash deposits, or it may be produced by crushing rock pumice. Porosity: Pumice is very porous, with approximately ninety% of its quantity consisting of empty spaces, making it a wonderful content for h2o retention in horticulture. As https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/