Help to identify a fruit?

[CambsForagers]

Hi all, I wonder if anyone can please advise what type of fruit this is; we feel it might be Greengage, but an extensive search on the internet has drawn a blank. Many thanks for all your replies :-)

[veggiechicken]

Hi and welcome!! Is it a walnut? Cut it in half and you should see the shape of the nut

[rustylady]

How big is it, and do you have any pictures of the tree it came from?

[FB.]

Hi and welcome!! Is it a walnut? Cut it in half and you should see the shape of the nut

Looks like an unripe walnut to me, too.

The shape and size of the leaves will confirm it.