Polishing characteristics and problems Pyrrhotite, chalcopyrite,
magnetite and pentlandite. Kambalda, Western Australia The
section has been partially polished with 6µm diamond paste.
Individual grains of pyrrhotite (brown) are clearly seen due to
differential polishing. Crystals in some orientations still
retain many polishing pits (black) whereas others are well
polished. Chalcopyrite (yellow, centre bottom) and magnetite
(light grey, bottom right) are present. Pentlandite (pale
yellow-brown, centre right and close to a diagonal fracture) has
higher reflectance than pyrrhotite and is just visible within
the largest pyrrhotite crystal as small pentlandite flame-like
exsolution bodies along a fracture- Dark grey area (bottom
right) is silicate, black areas are polishing pits. Coarse
features, especially grain boundaries, are well shown after
initial polishing, but fine features are still difficult to see.
llmenite and haematite. Kimberlite pipe. Unknown Provenance This
section has been polished with 1µm diamo