A rapid fusion technique is described in which the Li₂B₄O₇ bead is polished, not crushed. The reliability of the technique is illustrated by a series of precision tests and analyses of standard rocks, using a 2:1 Li₂B₄O₇ : rock-powder dilution. It is also pointed out that such a low-dilution fusion method may be used for Na₂O and trace element analyses with only a small loss in sensitivity relative to the unfused-powder method. Any fusion method has the advantages of greatly reducing absorption effects and eliminating particle-size effects.