Natural mineral. Mineralogically, Green Porphyry stands between porphyry and celadonite sandstone. Green Pophyry from the Maritime Alps in the South of France is a result of volcanic processes. Until the middle of the 20th century, the German chemical company BASF extracted the green stone from the Maritime Alps and sold it as French green earth. On the southern side of the Alps, there are numerous occurrences of color that do not fit with the other mineralogy of the Alps, but instead with the mineralogy of Africa, since Italy geologically belongs to Africa. Examples are the original Verona Green Earth as well as the green stone Green Porphyry, furthermore Venetian Red and Italian Gold Ochre Light. In color and characteristics, the green pigment made from green porphyry is similar to Bavarian green earth. However, in contrast to that pigment, Green Porphyry is less reactive, therefore it can also be used in acrylics and with silicate binder.
