The phrase can be utilized synonymously with "volcanic ash." It's mined from volcanic ash deposits, or it can be made by crushing rock pumice. Porosity: Pumice is extremely porous, with approximately 90% of its volume consisting of vacant spaces, which makes it a superb material for drinking water retention in https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/