Well the only thing I can tell you is to weigh it. Other than that if it's pretty close to 3.11 grams it's right metal
Just based on the picture this penny appears to have an interesting patina, but looks to be the normal copper. Of course I'm no expert.
We have been through this a few times. Fred Weinberg posted the copper Lincoln cent tolerance at 2 grains. ( 2.98-3.24) 3.29 is over that tolerance.
You should also check to see if your scale is on a flat surface and properly calibrated (not always easy to do if you have an inexpensive scale and no calibration weight). A quick check is to take 10 coins and weigh each of them. If they all weigh close to spec (3.11 or 2.5 gms for cents), you're probably OK. This IS NOT a scientific way to check your scale, but it will give you an idea if your scale is working properly.