Volcanic Ash

Also known as Pumice, volcanic ash is a unique material to use in glaze formulation. Volcanic ash consists of extremely fine particles of volcanic glass that have been ejected and then settled in layers. Because this rapid ejection results in a rapid cooling of the glass particles, volcanic ash is actually non-crystalline -- and this factor imparts unique melting properties on recipes in which it is used. FFF grade Geologically, volcanic ash is a type of feldspar. Chemically, it is very similar to granite or rhyolite. Because the source of volcanic ash varies so much throughout the world, there really is no one representative deposit. As such, if you are a frequent user of volcanic ash you may notice variations within different batches. Keep in mind that this can result in notable variations between batches.