About 60 beryl samples, nearly all from Precambrian granite pegmatites, were examined by optical spectrography. Li contents range from 0.07 % to below 0.005 %. One single sample showed as much as 0.2 % Li. The variations are quite local; averages for the Østfold area and the Iveland-Evje area are nearly equal, about 0.025 %. Cs contents in excess of 0.05 % are recorded in a few cases only.
Lithium contents of Norwegian beryls