Hello all, first time post here so hi.
I was field walking a few weeks ago and literally stumbled over this strange item half-buried in the chalky soil. My immediate concern was that it was an old Mills grenade left over from Home Guard practice - it's palm-sized, so I took several smart steps backwards. Closer investigation showed it to be a mineral/stone and not metal, so I'm stumped as to what it might be. Some pics here - hoping someone can give me a clue as to what I've found...
Thanks in advance...
It is a marcasite nodule, and a nice one at that.
Chalk is a common place for them to occur. In this situation they are usually rusty in appearance.
You can see some fibrous-ish structure on the outside of your specimen. That can be more pronounced and fairly spectacular on the inside- like here - http://piclib.nhm.ac.uk/results.asp?image=028744
Thanks Mike - I think that nails it, there are quite a few similar on the web - I am quite tempted to have it professionally cut to see the interior... Although a big part of me thinks that would be just a bit wrong, as the nodule has taken so long to get this stage...
Anyway, thanks again Mike,
If it has a damaged/defective side/spot, consider sawing off that bit (and a bit more).
That way, you will both see inside and have a flat surface for it to stand on (it will be on display somewhere, I'm guessing), yet it will be ostensibly still intact.
If you do saw it and find something nice inside, please post a photo here!