As part of my collection of coins from 1916 (allegedly for my kid) I have been trying to get the Gold 100 Piasters from Egypt. 

It's a one year type, also known as AH 1335 in the Islamic calendar.  Struck under authority of the British occupation in the middle of World War One when the Ottomans were on Germany Austria and Bulgaria's side.  You can get piles of the 20P 10P and 5P silver coins of the same year, and also from 1917, but the gold ones are tougher.  Although, watching Heritage auctions, you'd notice there usually are a few up every year.  So I won one of them late last year, a PCGS MS62, and I sent it to NGC.  They determined it was "NOT GENUINE" and sent it back.  Heritage bought it back from me.  Good people.

So I really wanted it then, and I bought another one from an EBAY seller, this time in the old style NGC holder also graded MS62.  I sent it into NGC to reholder in the new style holder.  Guess what?  NGC decided that one wasn't genuine either!  They did the right thing and bought it back from me at the price paid to the Ebay Seller.  Can't blame the Ebay seller for selling an NGC graded coin.

What's the give away?  I asked NGC, they didn't tell me.  Any advice?  They said to buy NGC certified examples!  I tried that.  But of course there doesn't seem to be a lot of better alternatives to trying again.  Next time I get one I should just leave well enough alone.  

The numismaster listing for the coin says "prooflike restrikes may exist."  Nobody has confirmed that this is what I have been getting and sending in, but, maybe that would explain it.  Or it is just a highly faked coin.  Anyways I thought I would share this experience of buying two actually-certified examples of the same coin that both were later determined by NGC to be not genuine.  And, its nice to know both Heritage and NGC stand behind their businesses.