The lages pintadas aquamarine deposits, ene Brasil: a new gem Province and a new model

Résumé

Granitic pegmatite domain of the Borborema Structural Province is one of the most mineralized of the Brazilian pegmatite provinces. One aquamarine gem province and one tourmaline gem province have been defined by Baskara Rao et al, (1998), south of the town of Parelhas in ENE Brazil. They are characterized their geological, lithological, and structural conditioning, respectively in the biotite schist dominated synform, and banded micaceous quartzite antiform. The mineralized pegmatites where abandoned and now are beginning to be reworked, sporadically, with the occurrence of gem pockets which result in an osci1lating gem production of aquamarines and tourmalines in the region. The Lages Pinta- das area, NW of Santa Cruz, has pegmatites hosted in Archean migmatitic-gneissic complex  (TTG ?) with excellent crystals and large fragments of aquamarines with pleasant water blue color and hue. They are excellent for lapidary purposes and fetch good to high returns. The geological conditioning, structural positioning, lithological controls and pegmatite/quartz vein type mineralization permit the denomination of a new model and also a new province.