Ferberite (Var: Reinite)
Barruecopardo Mine, Barruecopardo, Salamanca, Castile and Leon, Spain
Reinite spongy mass.
The Reinita is not a mineral species, it is a pseudomorphism of Ferberite seconds Scheelite.
It is formed when Fe-rich solutions, originating from the alteration of sulphides (pyrite) react with the Scheelite and transform it into Ferberite, with loss of volume, which gives the aspect spongy.
Specimen from the merchant Juan ...