It looks like yellow metal in that scratch. It shows up as yellow metal against the green.
I think you are from Ga. as I am. Generally, copper degrades a penny with a rough covering of green oxidation. This thing looks odd since the oxidation looks smooth and green.
Hope you find out what kind of metal does that after being in the soil for a long time. Great but odd find.......2.2 OZs.....ouch!
Just thinking about it, I would think that lead would weigh more on a ball this size. It would be white like a mini ball if it was lead anyway.