I found what looks like a rock. I need some help to determine what it might be. It is not lead as it is too light. It weights only 14.4 grams. It is NOT magnetic. The VDI is +80 (with 87% confidence) and the polar graph has all three frequencies in the upper right quadrant, so it should be something good. I suppose that there could be a coin completely encased in this rock-like material but it's hard to imagine given the apparent hardness of the material. Any ideas would be greatly appreciated.