Tesaurus d'Art i Arquitectura Getty Institute 0000-00-00 2024-01-24 15:40:44 en pumice300011250 A pale gray, porous variety of the volcanic stone rhyolite; it is composed of potassium aluminum silicate with small amounts of iron and alkalis. Pumice is used as an abrasive for polishing jewelry, cleaning metals, and smoothing vellum and parchment. In its solid form it is used as an abrasive and aggregate and in its powdered form it is used as a polish and abrasive. pedra tosca piedra pómez 2026-03-30 21:06:49