Interesting 1907 Indian Head Cent

*** Moved by Staff to a more appropriate forum. ***

I was cleaning up from my last batch of coins I searched and found this odd Indian Head cent I had kicked off to the side. On 1st look appears to have been dipped in mercury at some point - maybe? It is missing a small amount of material in the center of the wreath but not much. I accidentally dropped it on my desk and it has a high pitch ring to it. Does not sound like a copper coin. For fun I weighed it and it shows almost half of what it should weigh at 1.84grams. Standard weight should be 3.110 +/-.130 (grams).This is puzzling to me as it is not missing that much material and if it does have mercury on it you would think this would make up for some of the missing material as mercury has a density almost double that of copper 13.5 g/cc vs 8.96 g/cc. I did calibrate my scale before weighing it. I just thought this was interesting and while I do not think this is anything special I could not figure out the weight discrepancy. Any ideas about this? Thanks for your input!