But at Val Graveglia a number of minerals with essential vanadium in their structure have been found: gamagarite, haradaite, medaite, palenzonaite, Pyrobelonite, reppiaite, saneroite, tangeite, vanadomalayaite and volborthite.
In this last case the association is quite interesting, showing cuprite, volborthite and several arsenates.
Probably the most interesting specimens are those found in silicified wood, associated with volborthite, several arsenates and, in places, connellite and spangolite.
The associations include quartz, cuprite, azurite, chalcophyllite, volborthite and other secondary As and Cu minerals.
Volborthite [[Cu.sup.2+].sub.3][[V.sup.5+].sub.2][O.sub.7][(OH).sub.2]*2[H.sub.2] O
Volborthite was the first vanadium-bearing mineral described from Val Graveglia (Cortesogno and Galli, 1974; Antofilli et al., 1983).
The associations include volborthite, native copper, connellite, arsenates and other copper minerals (Palenzona, 1996).
Excellent specimens of crystallized volborthite have been exposed locally throughout many areas of the deposit.
Turanite: apple-green platy crystals associated with malachite, carbonate-fluorapatite and barite have been shown by XRD to be volborthite.