Geology

Rodingite is a name for those rocks composed prevalently of garnet or other calcium silicates , and associated with weakly metamorphosed ultramafic rocks which are present in various parts of the world.

In Italy those kind of rocks are better known as Granatite (an old name) and generally are associated with the serpentinized ultramafic rocks of the Western Italian  Alps. For the most part they are lenticular and are characterized by the presence of lithoclases with very beautiful crystals of garnet, sometimes in paragenesis with a few other minerals.Similar lithotypes , much more rare, can be formed with a preponderance of vesuvianite , epidote or diopside. Their formation was , in the past , assigned to contact metamorphic processes of carbonate rocks tectonically included in the ultramafics or to the transformation of original gabbro bodies.

Localities

There are many localities in the North - West of Italy where is possible to find these kinds of rocks, even if the site are usuaully small and the rodingite dikes do not exhibit for more than 10-15 meters.

Here are the most famous area :

• Liguria:
  Passo del Faiallo, Bric camulà , Rocca della Biscia, Rocca Marasca, Bric Mundù

• Piemonte
  Val Pellice, Val di Susa, Val di Viù , Val Chisone, Val d'Ala ( Testa Ciarva, laghi Verdi), Antronapiana

• Val D'Aosta
  Bellecombe, Montjovet, Ponte delle Capre, Monte Rosso di Verra, M.Te Barbeston

• Lombardia
  Val Malenco - Laghi Cassandra
  

It's also important to say that almost all the main sites are inside Natural parks and now collecting it's forbidden .

The minerals

The minerals of the "Granatite" are not numerous,but there are very nice samples not always known in the collectors world.

Grossular var. Hessonite: occurs as very bright XX from dark red to vivid orange usually in rhombododecaedrical crystals up to 2 cm

Vesuvianite: Usually this mineral forms green to brown  columnar and stacked XX up to 3-4 cm ( some of 10-15 cm are known) very bright

Epidote: occurs in dark green  crystals usually forms own lithotypes in association with diopside.

Diopside: Occurs as bright  white - green  XX up to 4-5 cm usually associated with hessonite, epidoto. vesuvianite.

Other than those main minerals it's possible to find other species in association such as : apatite, titanite, clinocloro, magnetite, zircon, prehenite, perowskite.