This page contains a selection of micro-photos of polished sections used in the course "1655 Ore dressing - Environmental Geochemistry of Mine Waste Management (R. Lehne, B. Dold)" offered to the graduate students of the Universities of Geneva and Lausanne (other participants are also accepted, see conditions and dates under http://www.geoleman.ch/ (look "programme des cours").
Download PDF script with sketches and tables (1.3Mb): Treatment and microscopy of gold and base metals ores.
Other related links:
Introduction to ore microscopy
http://cms.unige.ch/sciences/terre/research/Groups/mineral_resources/opaques/opaques_menu.phpRecommended abbreviations for ore microscopy
http://cms.unige.ch/sciences/terre/research/Groups/mineral_resources/opaques/ore_abbreviations.phpAthena mineral databases. Search for formulas, names, references
http://athena.unige.ch/athena/mineral/search.htmlMicro-photos of selected gold ores and base metal concentrates (polished sections, reflected light):
1. Gold ore (Bibiani/Ghana).
Native gold occurs both free and as inclusions
in arsenopyrite.
Width of micro-photo corresponds to approx. 450 microns.
2, Gold ore (Callion/Australia).
Native gold in association with colloform
goethite indicates contemporaneous precipitation.
Width of micro-photo corresponds
to approx. 250 microns.
3., Copper concentrate (Neves Corvo/Portugal).
The concentrate is based on chalcopyrite.
It contains subordinate pyrite and accessory sphalerite and stannite.
Width
of micro-photo corresponds to 550 microns.
4. Copper concentrate (Ertsberg/Indonesia).
Heterogeneous concentrate based
on chalcopyrite and bornite with subordinate amounts of covellite and digenite.
There is also a considerable portion of pyrite.
Width of micro-photo corresponds
to 550 microns.
5. Copper concentrate (Ok Tedi/Papua New Guinea).
Copper concentrate based
on chalcopyrite and digenite.
There is also a substantial amount of pyrite.
Width of micro-photo corresponds to 550 microns.
6. Copper concentrate (Escondida/Chile).
Copper concentrate based mainly on
secondary copper sulphides such as digenite, chalcocite, and covellite.
There
are also abundant pyrite, minor amounts of chalcopyrite, and accessory molybdenite.
Width of micro-photo corresponds to 550 microns.
7. Lead-zinc concentrate (Song Toh/Thailand).
The bulk concentrate contains
both galena and sphalerite that cannot be fully liberated because of fine and
complex locking textures.
Width of micro-photo corresponds to 550 microns.
8. Zinc concentrate (Cayeli/Turkey).
The concentrate
consists of sphalerite with minor amounts of free and locked pyrite.
A
certain copper content in
the concentrate is caused by minute inclusions of chalcopyrite in sphalerite
("chalcopyrite
disease").
Width of micro-photo corresponds to 550 microns.
[Mineral Resources and Geofluids]
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