Mineralogical Magazine; April 2004; v. 68; no. 2;
p. 369-394; DOI: 10.1180/0026461046820193
© Mineralogical Society of Great Britain and Ireland
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FIG. 4. Altered primary minerals. (a) ENSM-6774. Fibrous slab of alteration Ir-Ru-Pt-Os oxide (dark grey, bronze colour under reflected light; Table 1, col. 4) still containing residual rutheniridosmine (white; Table 1, col. 3). Pol. sect. SEM(BS). 160 µm. (b) NHML. Particle of Ir-osmium (inner white residue) surrounded by rhythmic layers of alteration Ir-Os-Ru-Fe-Ti-Cu oxides (various shades of grey). Pol. sect. SEM(BS). 125 µm. (c) ENSM-6774. Altered Ir-Ru-Pt osmium (white; Table 1, col. 5) with thick crust of alteration Ru-Os-Pt-Ir oxide(s) (spotted grey). Pol. sect. SEM(BS).160 µm. (d) ENSM-6774. Enlargement of Fig. 4c showing fibrous microcrystals of Ir-Fe oxide, composing the crust and resulting from the alteration of the metal (Table 1, col. 6). SEM(BS). 10 µm. (e) ENSM-6774. Fragment of a large particle composed of laurite (light grey), rutheniridosmine (white, segmented) and Ru-Ir-Pt-Fe oxide (dark grey alterations of laurite). SEM(BS). 16 µm. (f) ENSM-6774. Particle of Os-Pt-Ru-iridium (white) containing hongshiite inclusions (grey), surrounded by a thick alteration crust of Ru-Os-Pt-Ir oxide(s) (spotted grey). Pol. sect. SEM(BS). 160 µm.
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