Opal
5553 Topaz, Opal, Conca Cannas quarry, Masullas, Sardinia, Italy
Prismatic and acicular topaz crystals, with opal coating tridymite, and also capping one of the topaz crystals, from the Conca Cannas quarry, Masullas, Mt. Arci, Oristano Province, Sardinia, Italy.