http://www.youtube.com/watch?v=jeYR3pT10C8
Do you have Half Sovereign which is 100% genuine? If you compare sound of both coins you will find if it is fake or not. Just spin both coins on...
Don't worry. There is the same kind of testing app for iPhone -> CoinTrust (www.cointrustapp.com). You will find it here: http://georiot.co/45jC
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