Ten years ago, on what I believe to be my first week of deciding to go all in as an error coin dealer, this error came up on eBay and I purchased the coin. When I got the coin in raw it was close to the size of a quarter but lacked the clad layers. Upon weighing the coin, it came out to an even 6 grams which is not the 5.67 grams a US Quarter should weigh. After consulting with Fred Weinberg we concluded the coin is indeed genuine and under further advise from Mike Diamond, I was able to access the list of planchets produced for foreign countries coinage. I found that the US Mint produced 6 gram planchets for the Taiwan Dollar in the early seventies. Bingo. I held the coin raw for 10 years until deciding to get it certified as a mint error by PCGS last year. It graded as researched.