Found a fruit.

Must have fallen off the big tree here in CM. Many along the path. Some semblance to an acorn, with the cap and the size, total about 1+ inch, sides of fruit flattened. But good lord, once i picked it up i wondered if this thing was natural or man-made.

The cap was light brown, covered about third of the entire but not flaky or loose. The bottom part was black and hard as a stone. And as heavy as one too. Tap the black part against the tile floor, just like two stones rapping. Hard and dense and to my knowledge could not be bitten into by ordinary animal. Possible an elephant could swallow and digest, or not.

Any ideas on this fruit? On this forum as could find no 'botany forum'.