Pietra dell'Etna, from Mt. Etna, Catania, Sicily, Italy
Geological description:
Tephrite. A porphyritic rock with euhedral white megacrysts of leucite and subhedral dark green megacrysts of alkali pyroxene, in a very fine-grained groundmass of feldspar and ?feldspathoid set in pale brown matrix. A few yellow ?olivines are visible.