Pietra dell'Etna, from Mt. Etna, Catania, Sicily, Italy
Geological description:
Mixed rock, possibly from a junction of intermediate and basic magmas. Patches of paler grey microporphyritic rock consisting of feldspars and sub-aligned euhedral pyroxene crystals. These have diffusion rims (containing carbonate) at contacts with the dark streaky-textured coarser rock, which contains larger crystals of feldspar and pyroxene.