On the occurrence of tin in Norwegian minerals

A large number of Norwegian minerals were examined by means of optical spectrograms. In the present paper are Iisted those which were found to contain tin. They are almost exclusively minerals from sulphidic ore deposits and minerals from pegmatites. (In some pegmatite minerals tin has been found earlier bv chemical methods. These are quoted, with references, as completely as possible.) Tin contents as high as 1 % are quite exceptional and have so far been found (not counting the nordenskioldine) only in samples of yttrotantalite, samarskite, thortveitite, and perhaps ilmenorutile. Tin contents lower than 0.001 % in sulphide minerals and lower than 0,01 % in the other minerals can generally not be detected by the method here applied, therefore these figures will mark the upper limit of the contents for !hose minerals in which no tin was found. Although !his investigation reveals the occurrence of tin in a considerable number of Norwegian minerals it confirms the general impression that Norway is particularly poor in tin: the highest percentages are found only in very rare minerals.