Any budding petrologists or geologists here? (rock ID)

[thetapeworm]

I was wandering around the Surrey hills last weekend (Crooksbury Hill) and kept finding rocks like this...



It's really heavy for its size but when I tried to look at geological maps of the area nothing like it popped up (that I could find anyway). Can anyone ID it?

Greensand kept coming up in searches for this area but it didn't look the same to me.

[thetapeworm]

Thanks!

The piece pictured is about 30mm wide so the components are quite small but it's definitely got a bit of extra weight to it.

I appreciate your insight and the time taken to look at this.

[thetapeworm]

And this is why I love Pistonheads

No matter how random the question someone always has some insight, cheers.

[thetapeworm]

Rock hard you might say.

There was a lot of it around in all kinds of sizes and shapes, some like broken slates, others small and polished.

I wondered if it might have been brought in to reinforce the paths but it was quite sparse for that purpose and not joined by other rocks.