Peterandresenite
Peterandresenite is a very rare mineral, the first known natural hexaniobate. Its chemical formula is Mn4Nb6O19•14H2O. Its structure contains a special type of octahedron: Lindqvist ion. Peterandresenite was found in a pegmatite of the Larvik complex in Norway. It is somewhat similar to other unique niobium minerals, aspedamite and menezesite.Occurrence
Peterandresenite was discovered in AS Granit quarry, Tvedalen, Larvik, Vestfold, Norway.