The occurring amid aged volcanic rocks, the cavities are frequently full of deposits of secondary minerals released by percolating h2o. The glass itself types threads, fibres, and skinny partitions among the vesicles. Rhyolite and trachyte pumices are white, andesite pumices generally yellow or brown, and pumiceous basalts (like happen in https://bookmarkspecial.com/story19583559/considerations-to-know-about-pumice-stone-wholesalers