Interesting discussion if somewhat worrying. I've tried to do some sums to better understand the difference between a 20 ct copy and a real sov. - please correct me if they are wrong. If 22 ct is 91.67% gold content then 20 ct would be 83.33% gold content. The difference in gold content between a real sov and a 20 ct copy would be 8.34%. 8.34% of 7.32g (total gold content of a real sovereign) is 0.62g So total gold content of a 20 ct jewellers copy would be 6.7g (0.2138 AGW) instead of 7.32g (0.2354 AGW). At todays price of $1671.46 /oz then a real sovereign is worth $393.47, a 20 ct copy would be worth $357.36 - difference of $36.11 Base metal in the 20 ct copy would comprise of 1.28g compared to 0.66g for a real one. Would this increase in base metal be slight enough to fool the Fisch detector or the old style sov scale and pass weight, diameter and thickness tests? It would be interesting to get the exact weight of the 20 ct copy to see how much it deviates (if at all) from the standard weight of 7.98g. It should be noted the Fisch does have a tolerance level of 0.7g which i think is too high.
