PHOTOS by ROGER WARIN & COMMENTS by ZELMIR GABELICA
I formerly cut a Sierra Colorada (Argentina, L5) and two of the slices obtained contained large (almost centimetric) vugs, some making the 3 mm thick slice hollow! Looking inside is again really breathtaking. Several 5 to almost 10 mm (!) euhedral metallic crystals (also pyritohedral in shape) can be seen, aligned or dispersed, some as quasi isolated single crystals, onto the vug walls. One of them is sectioned through cutting and that small cut face (clearly seen on 2 pictures) indicated to me, from the typical luster of the cut section, that these could be schreibersite (also possible, though perhaps less likely than troilite). See pictures 4741 and 4744. |
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