Vesuvianite (Idocrase) on Matrix
Val di Fiemme, Trento Province, Trentino-Alto Adige, Italy
Dimensions: 4.0 × 4.0 × 4.7 cm
Provenance: Original collection label, catalog no. 542, identifying the specimen as vesuvianite crystals on matrix from Val Fiemme, Tyrol, Italy. The original label's “Val Fiemme, Tyrol” is historical terminology. The modern locality is Val di Fiemme, Trento Province, Trentino-Alto Adige, Italy. Vesuvianite is documented from several sites around Predazzo, including Canzoccoli and Malgola.
A richly crystallized specimen featuring intergrown, stout prismatic vesuvianite crystals in warm honey-brown, amber, and olive-green tones. The crystals display well-defined faces, broad terminations, and a vitreous luster, with translucent golden edges that catch the light. A contrasting cluster of pale, translucent crystals occupies a central cavity, while smaller vesuvianite crystals extend across the surrounding matrix. The pale central crystal cluster is visually consistent with calcite.
Vesuvianite, also known as idocrase, is a complex calcium aluminum silicate that typically forms through contact metamorphism and metasomatic alteration of calcium-rich rocks. Its characteristic tetragonal crystals commonly develop in skarn environments, where mineral-rich fluids react with surrounding rock.
Val di Fiemme, in the Italian Dolomites, is a historic Alpine mineral locality celebrated for its contact-metamorphic mineral assemblages. The Predazzo–Monzoni area is particularly well known for vesuvianite, including substantial crystals associated with metamorphosed limestone.
