The occurring among the outdated volcanic rocks, the cavities are often crammed with deposits of secondary minerals introduced by percolating h2o. The glass by itself forms threads, fibres, and slender partitions involving the vesicles. Rhyolite and trachyte pumices are white, andesite pumices usually yellow or brown, and pumiceous basalts (such https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/