The phrase can be employed synonymously with "volcanic ash." It really is mined from volcanic ash deposits, or it might be made by crushing rock pumice. Due to its porous structure, pumice is Employed in soil mixes for horticulture. It helps with h2o retention, aeration, and drainage in potting soils https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/