Gold Coin .99999 Purity Vs .9999 Pure

The human eye isn't going to be able to tell the difference between 99.990% gold and 99.999% gold. They both "round up to 100%", as far as the human eye or any macro-scale analytical technique (like a handheld XRF) is concerned.

You'll also note that last line on the certificate about the statistic referring to the "bulk material" and not the surface. That's because at those trace levels, trace contaminants are likely to land on the blank planchet as it is being cut and prepared, trace dust is likely to be floating about on the mint floor and landing on the planchet before the coin is struck, small amounts of iron, manganese and other contaminants are likely to come off the coin dies as the coin is struck, and not to mention contamination from the various grippers, washers and other mechanical bits and pieces that touch the coin before it goes into the wrapper. So the surface layer of a .99999 gold coin is likely to be measurably less than .99999.

I wouldn't think shininess would have anything to do with purity. The higher the gold purity the more yellow it would look is my thought.
John1

Thanks so much all for all the great info!!! and yes, I was joking..i am hardly ever serious