The term can be employed synonymously with "volcanic ash." It truly is mined from volcanic ash deposits, or it could be made by crushing rock pumice. Pumice mining is often a floor operation as deposits are often Situated in close proximity to or in the Earth's surface in volcanic locations. https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/