pierre ponce

Note d'application

• (fr-FR) Pigment finement broyé à base de pierre ponce vocanique, utilisé pour fabriquer un émail transparent pour la céramique (AAT). A pale gray, porous variety of the volcanic stone Rhyolite. Pumice is composed of potassium aluminum silicate with small amounts of Iron and alkalis. Its spongy texture is due to numerous cavities formed by gas bubbles that were trapped when the stone solidified. The stone is lightweight enough to float on Water for months. Pumice is used as an Abrasive for polishing jewelry, cleaning metals, and smoothing Vellum and Parchment. It has also been used as a clear glaze on stoneware, as a matting agent and as a coarsening agent for texturizing painted surfaces. Pumice was quarried in ancient times from the Greek islands of Melos and Nisyros. Current production comes from Italy (Lipari Islands), Greece, Turkey, Spain, and the United States. (cameo)
• (en-US) Finely ground pigment made from pumice vocanic stone, used to make a clear glaze for ceramics.