Garnierite mineralogy in saprolitic ore of the Goro lateritic nickel deposit, New Caledonia , was investigated using X-ray diffraction (XRD), optical and scanning electron microscopy (SEM) and electron microprobe (EMP) analyses. These conspicuously, green-coloured phases occur either as submillimetre to centimetresized veins or as booklets' arranged in, macroscopic (subcentimetre sized), accordionlike structures supported in an undifferentiated matrix of mixed 7 and 10 phases. Within the veins, nickel for Mg solid solution increased from ten wt per cent NiO at the edge to 34 wt per cent NiO at the core, with vein edges comprising Ni-kerolite with <1.5 ni per formula unit (pfu) grading to pimelite containing>1.5 Ni pfu at vein cores. The booklets' comprised npouite of formula, (Mg0.67Ni1.59Fe3+0.05)(Si2.17Al0.22)O5(OH)4 and averaged 30 per cent NiO. SEM element mapping highlighted the distribution and mineralogical association of Ni and Mg and emphasised the inverse relationship between Ni and Mg at the macroscopic (thin-section) scale._x000D_
AnEXTENDED ABSTRACTis available for download. A full-length paper was notprepared for this presentation.