Not sure what coin you're referring to, but the OP's coin has less than $0.70 worth of gold in it according to his estimated weight and composition. Here's the calculation: 4.4 grams x 0.41% gold = 0.01763 grams of gold Since one troy ounce is 31.1034768 grams, this is 0.000566818 troy ounces of gold Assuming gold is about $1,225 per troy ounce, this is $0.6944 worth of gold. Maybe you were thinking of another coin?
Folks reading this thread must think I'm seriously lacking education. (I know Ag is silver and Au is gold). Somehow I had it in my head that the coin had 69.47% gold in it. Oooops.
Showing my ignorance: If I sent 2000 of these to be melted, would it be practical to extract the tad over an ounce of gold from them or would the cost of extraction of that percentage make them take the silver and send the gold out with the slag? I know small amounts of gold can be extracted from waste ore but at what point is the silver lost in the process worth more than the gold gained? As I recall silver and gold are harder to separate than most other combinations. As we see it, the coin is worth 10-30x melt so anyone stupid enough to consider that option really needs another hobby.
Also, am I not correct that the x-ray technique is one that only measures the surface so the melt percentages of the whole coin could be a lot different? 69% AR seems high for this period unless the flans were surface enriched.
I suspect the surfaces were naturally "enriched" after spending umpteen centuries in slightly acidic soil, effectively accomplishing depletion gilding.
Most interesting! I had to look up depletion gilding, but perhaps that's what accounts for the slightly golden hues on the coin, if it's a true-color image.
Here is another shot with great attention being paid to the true color... I wanted to eliminate the conclusion the the coin is gold color, it is not. The coin does have a soft yellow patina in areas.