Boron distributions in single crystals investigated with nuclear reaction micro analysis

Crystals synthesised in the laboratory in B-rich fluxes were analysed with a nuclear microprobe and nuclear reaction techniques for boron distribution and concentration determination. The synthesis technique and the principle s of the elemental analysis are discussed and some analytical examples are shown. The geological problem, a B-Si substitution, is described with some conclusions. The zonal B-pattern observed in Mn3+-substituted diopside clea rly demonstrate that the present analyses represent structurally bound B an d the observed variation in Na- and B-concentration ratios provide evidence for a decoupling of the suggested substitution mechanisms in clinopyroxene . (C) 1999 Elsevier Science B.V. All rights reserved.