PREPARATION, HOMOGENEITY EVALUATION AND COOPERATIVE STUDY OF TWO NEW CHROMITITE REFERENCE SAMPLES CHR‐PT⁺ AND CHR‐BKG

Abstract

Two chromitite samples from the Isles of Shetland (North Scotland) have been processed, each in 200 kg quantities, as reference samples for the determination of gold and the platinum‐group elements (PGE). One of these samples, Chromitite CHR‐Pt+ is enriched in the PGE and the other, Chromitite CHR‐Bkg has much lower concentrations. A detailed assessment of sample homogeneity is presented, together with the results of a cooperative study by thirty‐five international geochemical laboratories, private and public. Contributed data together with derived working values are presented for Au and the PGE as well as for major, minor and a few trace elements. It is hoped that this first compilation report will encourage additional laboratories to participate in further studies of the PGE in these two CHR samples.

Platinum‐Group Element Geochemical Certified Reference Materials (GPt1‐7)

“…To date, few geochemical CRMs with PGE at the ng g -1 level have been prepared with satisfactory homogeneity to permit certification and use in applications such as geochemical exploration. Yet without such reference standards, it is difficult to demonstrate improvements in analytical methods for trace and ultratrace or to make progress in geochemical exploration and fundamental research on geochemistry of the PGE in relation to the formation of platinoid deposits (Potts et al 1992, Yan and Chi 1997, Sun et al 1997. It was to satisfy these requirements that the certification programme for RMs, GPt1-7, was initiated.…”

1994 Report on Whin Sill Dolerite Ws‐e From England and Pitscurrie Microgabbro Pm‐s From Scotland: Assessment by One Hundred and Four International Laboratories

“…The candidate reference samples, Dolerite WS-E and Microgabbro PM-S, are respectively the fourth and the fifth sample to be processed in co-operation with the Open University within the framework of the IWG, the three other samples being the Granite AC-E (1) and the two Chromitites CHR-Pt+ and CHR-Bkg (2). The collaborative study of WS-E and PM-S was completed in only nine months; from October 1993 to June 1994.…”

Spatial Geochemistry: A Characterisation of Heterogeneity in Reference Materials

“…The material is expected to be finer than 75 μm for CHR‐Bkg, CHR‐Pt+, (Potts et al . ) WMS‐1 and WMS‐1a (Leaver and Salley ), while MASS‐1 and MASS‐3 are expected to be much finer because they are chemical precipitates (Wilson et al . , Wilson ).…”