That is an extremely rich pan. If it were a pan from even 20 pounds of river gravel, I would sacrifice a lifetime's earning trying to get that one into production. It could be a "demo", or from the clean-up of a sluice box. More often, Platinum will be finer than that.
In a true "pitch-up" of a pan, the valuable grains will not be scattered as in the photo, but will be at the "sword-tip" of a scimitar-shaped grain-trail along the bottom edge/groove of the pan. "Pitching-up" is an olde English expression. (Panning is 2000 or more year-old art in Britain.) The technique is to tilt the pan toward you at about 30 degrees from the horizontal, with about a cup or two of water and a half cup or less of heavy minerals from panning. You rotate the pan to the left with an oscillatory shimmying or tapping action, and let the water swirl counter-clockwise around the bottom groove of the pan. (You might have to alternate the wash with the shimmy, as it is hard to co-ordinate). The water washes over the minerals in the "pocket" of the pan and lifts the lights to the right. The minerals will separate with all the super-heavies on the left in an "eye", and the less-heavy will wash over to the right. A trail then begins to form, with the gold and Platinum forming a long curved path and a bright spot at the left-bottom. This is the proper way to examine a pan concentrate.
In a heavy Pt river the eye will be whiteish ahead of the gold. Silver also pans well, but it is lighter than gold so more to the right, and the grains will be slightly larger.
Yukon News--->
It seems like the federal DFO (Department of Fisheries and Oceans, desperately seeking excuses to run Yukon placer miners out of business, is seeking to injunction that placer miners will no longer be able to discharge tailings water into the Yukon River. It is rumoured that the new regs will shutdown 85% of placer miners. This will destroy the economy of the Yukon. There are not many votes in this, so the Federal liberals, long anti-mining, and more anti-western, English speaking mining, are not concerned.
I don't know just how stringent the regs are. If they allow two tailings ponds, reasonable sediment settling and cleaning, or just disallow bank diggings in the river bed. I heard that some arbitrary figure of 40 metres removal from a river bank or the Yukon river bank was required. Historically the Yukon is a very muddy silty river. It discharges and reloads at any one point perhaps 1,000,000 tons of sediment in a 24 hour period. (both pick up and drop out) A placer claims will discharge at the most 750 tons of gravel per day, of which is perhaps 100 tons is fine sediment. 10,000 to one seems like a miniscule amount by comparison, doesn't it?
Since load is constant, and sand drops out as fast as it is picked up in sedimentary systems, all the placer mines of the river do not add any net sediment load to the river as a whole. The river can only carry the sediment that it can carry, according to its flow rate. It cannot carry any more of any particular size range. The only sediment addition it can possible additionally carry, is the very, very fine clays of which i has plenty anyway, which do not settle. If the clays do not settle at all, or very, very slowly, they are not a problem. All sediment load that buries fish breeding grounds or eggs, has to be local and should be trivial. If there is any sediment discharge from tailings, it can be reduced to zero by settling ponds, flocculants, and cyclones. Te discharge can be cleaner than the river.
The small amount of sediment a 1000 placer mines can add to river as mighty as the Yukon, is trivial to the natural environment. Translation is, the knee-jerk reaction of the DFO, who has not a sedimentologist on the entire staff, is bad science, and very jejune. The fact that the entire placer mining history of the Yukon has not resulted in any reduction of the fish or benthic population in 100 years, should be examined at bit more closely.
It is far more likely that if fish stocks are declining that fishing offshore in Alaska, by Russians and Americans is the cause. We have seen this before.
EC<:-}
