Is this even a fossil?

I'm afraid I can't be much use with details of where this was found. My mum gave it to me more than 2 years ago when I started me Geology degree, she found it in our back garden in Essex. Our back garden was the last to be finished when they built the estate so it had generally been used as a temporary construction dumping ground so this fossil was definitely not in situ and I can probably only narrow its origin down to "around Essex"

Anyway, I remember she gave it to me because it does look trilobite shaped but I was never convinced it was a fossil, I still think its possibly a cast of some construction material, or an actual piece of construction material! But I dug it out recently anyway to look again.



Here's an album with a few pictures. What do you think?

It looks like banded flint to me.

I think it's a trilobite shaped banded flint