VDI NUMBERS FOR PURE GOLD?

[Tammyjefferywilliam]

If I ground balance my Garrett AT Pro in my own yard in pro zero mode with discrimination set to 00 and hold the coil the same distance above the earth, then why do I get two different readings for two different 5 gram gold bars if they are both the same size and both supposedly pure gold? One reads around 80-81, but the other reads 88. Does that mean it's a fake?

 

[galenrog]

Try the same thing with two lead bars of the same size and you will likely get similar results. The VDI for one bar will differ a bit from the other. This does not mean the bar or the detector is a fake. It means the soil mineralization from one point in your yard to another is different. This is not uncommon in any area that has seen construction due to the amount of earth that gets moved around. Nearby metal concentrations can also skew the VDI readings.

You are doing well to question what your detector tells you. Keep plugging away and you will do well with the AT Gold.