The term may be used synonymously with "volcanic ash." It can be mined from volcanic ash deposits, or it could be produced by crushing rock pumice. Geologists recognize likely pumice deposits by studying volcanic action and inspecting surface area outcrops of volcanic rocks. Aerial surveys and floor-based mostly sampling in https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/