[Iwonda (OP)]

From what I've read, fossilized steinkerns are mostly made of sediments. Is it common to find hundreds of crystalized steinkerns in one area??

[evan_au]

I had to look it up....

Etymology - From German Steinkern, from Stein (“stone”) + Kern (“kernel, nucleus”).
Noun - steinkern (plural steinkerns)
A fossil formed from sediment that filled a hollow structure such as a shell.

[Bored chemist]

Some areas a known for their fossils.
When I was at school we used to go here
https://ukfossils.co.uk/2007/03/18/robin-hoods-bay/
 for educational trips.

[Bill S]

http://www.discoveringfossils.co.uk/walton-on-the-naze-essex/

Back in the 70s & 80s, when we didn’t have to wear silly hats, I used to take groups here.  Casts were not common, due to the sandy nature of the deposit; but at some levels, clay and iron concentrations change this situation. 

[Iwonda (OP)]

Some very good info, thanks for the articles.