Where was it found, on the ground or hanging from somewhere? If on the ground I'd say a puffball toadstool, hanging up maybe the start of a wasps nest. How big is it?

I found it on the floor in some woodland, it's about 1 1/4 wide & hard if squeezed

I've seen these before. Pretty sure it's a fungus of some sort. More investigation needed.

Do you think it could be a truffle ?

They are normally knobbly, but they are found mostly in beech woods. There are so many different types of toadstools that it's hard to say. I should be interested to know what it is and will keep looking.

I would be very interested to know exactly what it is, to push your thumb in isn't possible, I very much appreciate your help !

Google Common Earthball. It says it's quite firm and doesn't squash. Btw it's poisonous.

I'll look into that, thank you so much for your help, much appreciated !!

Had a look at several images which show good detail & I'm 90% it isn't a common earthball, I'm wondering what it is ?

No not an 'earth ball' but no idea what it actually is!

If it's not an earth ball, then maybe it's a moon ball MG? ;o)

The mystery continues. Cut it in half even if it's to prove its organic.

I've had to use a hammer & chisel to cut it in half, I think it's wood ? I've had a very experienced gardener look at it & we're very confused, I've taken a couple of pictures but can't see how to add them to the post ?

It's probably a stray golf ball!

Could be Cammomile

It looks like it has been formed with layers. Could it be some kind lime or calcium built up over time. From what or where is another mystery.