The Zeehan slag dump contains residue material from lead...

• The Zeehan slag dump contains residue material from lead smelting over 100 years ago.
• It includes 450,000 tonnes of material grading 13.4% zinc, 1.7% lead, 54g/t silver and 50g/t iridium

http://www.cordellconnect.com.au/public/project/ProjectDetails.aspx?uid=243156


Cant find to much more info to confirm, but i hope they drill and assay the heap now...
the in-situ value of the iridium is 4* that of the zinc


http://www.treasureenterprises.com/...ation/gold_prospecting_locations_Tasmania.htm

The West Coast was for a long time the largest producer in the world of the rare mineral 'osmiridium'. In the early days of alluvial gold mining, it was considered a nuisance by many diggers for it had a greater specific gravity than gold and was difficult to separate from it. The metal is of a steel-grey colour, and it was recovered in the same way as alluvial gold. Osmiridium consists of the two metals 'osmium' and 'iridium' in varying proportions, and minute traces of palladium, platinum and rhodium.