What Is This?? Answer included. [Picture]

My husband and my daughter spent quite a bit of time uncovering this. Do you know what it is? It's of the earth. It's not meat. Those are your only clues. I'll give you the answer on Friday, May 10th.

----Okay, lots of good guesses, but no one guessed correctly. This is a Mango seed. Not easy to remove from the husk. Ours looks more like a big pistachio when removed, more grey color. Here's a video on how the whole thing is uncovered.