Where is it found?
Vesuvianite was first discovered in 1795 by Abraham Gottlob Werner as he was studying the minerals around Mount Vesuvius in Italy, hence the name. Several years later another mineralogist, Rene Just Huay, suggested the name Idocrase after more of the stone was found in other parts of the world.
The two names are fairly interchangeable with some regional names like Californite distinguishing the massive form found in that state and Cyprine which denotes blue Idocrase that has trace elements of copper and is named after Cyprium, the ancient name for copper. A note here; though the names are fairly interchangeable, the name Vesuvianite does take precedence.
Vesuvianite is found worldwide in volcanic areas that have been subjected to contact metamorphism with significant veins being found in Italy (Mt Vesuvius), Canada (Asbestos), California (Siskiyou County), the Ural Mountains of Russia, and most recently in China (Fushan, Hebei Province). Cyprine, the blue variety of Vesuvianite, has been found in New Jersey (Franklin), Sweden (Jakobsberg Mine), Sri Lanka and Pakistan.