Proper sample preparation is very important for quantitative X-ray fluorescence analyses. Our first approach to fusing geological samples was a slight modification of a method described by Taggart(l) of fusing in platinum crucibles, with 1 g of sample to 10 g lithium tetraborate fired over bunsen burners. This method provided good results and was used until recently. Due to physical constraints, the required exhaust hoods could not be installed which prompted our investigation into new methods of fusion. The first reported application of a borate-glass fusion was in 1913(2); the melt consisted of 0.3 g of sample, 1.5 g of lithium carbonate, and 1.5 g of boron oxide (or about 3 g of lithium tetraborate). This mixture was heated in a graphite crucible at 1150 °C for twenty minutes and then poured into a brass ring on a copper-surfaced hot plate. Ironically our current procedure resembles this early technique.