Pietra del Vesuvio, from Mt. Vesuvius, Naples, Campania, Italy
Geological description:
A calc-silicate skarn. It is medium to coarse-grained, and contains irregular patches with concentric zonary structure, interior part of carbonate stained brown in places and acicular crystals of dark green amphibole passing outwards through zone of same mineral assemblage but more granular crystal form into outer zone of white carbonate (aragonite?).
Comments:
This sample is from a block of limestone caught up, metamorphosed, and ejected from Somma or Vesuvius. Such rocks often have cavities lined with well-formed crystals of a variety of different minerals, some quite rare. Small slabs of the various stones from Vesuvius were sold to 'grand tourists'. For example, when Jane and Mary Parminter returned to England in the 18th century, they had their souvenirs inlaid in a table-top, now to be seen at A La Ronde, a National Trust Property in Devon, England.