What are these cyllindrical stones?

August 11, 2009 12:01 PM

What kind of stones are these? Perhaps something fossilized?

I also took a close up of one piece. And while you don't really see it from the photograph, the pieces are kind of translucent, like quartz.

They were found on a beach in south-east Denmark in case it matters. All spread out too, so while they have broken off something they aren't all part of some huge stone cigar.

posted by bjrn to grab bag (7 comments total)

You might find this interesting....
posted by HuronBob at 12:11 PM on August 11

They're Belemnites. I used to collect them as a child in the UK so I guess they're common in North European gravel.
posted by rhymer at 12:14 PM on August 11 [2 favorites]

they look like calcite. The circular section makes me think of stalagmites. Do they fizz if you drop a piece in a little vinegar?
posted by _dario at 12:22 PM on August 11

These definitely look more like mineral specimens than proper rocks, though it's difficult to tell from just a photo. I'm anxiously awaiting the results of the vinegar test (just a few drops should be enough). If it gets fizzy, it's probably a carbonate mineral, such as calcite, or one of its pseudomorphs. Of those, (and given the shape) I'd put my money on ikaite, or more specifically, one of ikaite's stable pseudomorphs. (Disclaimer: it's difficult to ID unknowns when you're holding them, much less from a picture. )
posted by Eumachia L F at 1:29 PM on August 11

Belemnites sounds like the best answer. Interesting that _dario suggests calcite, evidently most Belemnites are calcite fossils.
posted by Xoebe at 4:10 PM on August 11

I think that they may be fossil rugose corals or Belemnites as stated before. They will have very different "ends" to them. So look for images that show the cross section and you should be able to figure it out.
posted by rvrlvr at 6:48 PM on August 11

I think they look like belemnites, thanks! I don't have any pieces at hand, so I can't test the vinegar thing though.
posted by bjrn at 8:32 AM on August 12