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What is this rock? UK origin, non metallic, heavy


closed as off-topic by user12525, Peter Jansson, Jan Doggen, arkaia, Fred Jul 13 at 17:20

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  • "Please review our rock identification guidelines to provide the missing information so that your question is both answerable and useful to new users." – Community, Peter Jansson, Jan Doggen, arkaia, Fred
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    $\begingroup$ Please read the guide for asking rock identification questions and edit your question to add the necessary detail (and fix your broken image link). $\endgroup$ – Pont Aug 3 '17 at 14:32
  • $\begingroup$ en.wikipedia.org/wiki/Coal_ball Coal ball maybe? I read about these recently. $\endgroup$ – Mike Aug 3 '17 at 14:37
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    $\begingroup$ The UK has an extremely varied geology (arguable the most varied of any country of the same size). Where in the UK? If heavy, then I would suspect something man-made. Naturally occuring heavy minerals in the UK are/include barite (this is NOT barite) in Scotland; and tungsten ores (which I don't know anything about) from Cornwall/Devon. $\endgroup$ – winwaed Aug 3 '17 at 18:02
  • $\begingroup$ Possible duplicate of What are these metallic nodules that were found at low tide on the UK south coast? $\endgroup$ – theforestecologist Aug 7 '17 at 15:36
  • $\begingroup$ @theforestecologist Not a duplicate: metallic vs. non metallic $\endgroup$ – Jan Doggen Aug 7 '17 at 18:50

Your rock is most likely a marcasite nodule. These nodules weather out of the chalk beds along the coast.

Here is a reference to UK chalk beds.

If you are interested, I would like to trade for one. I'll trade you a nice pyrite nodule I found here in northern Ohio near Lake Erie.

See this similar question: What are these metallic nodules that were found at low tide on the UK south coast?

  • $\begingroup$ worth adding, marcasite is non-magnetic even though it is make of iron and sulfur. $\endgroup$ – John Oct 8 '17 at 15:45

Not coal... coal is very low density, so wouldn't be "heavy."

Looks like an ironstone concretion. It looks suspiciously like a sectarian nodule (google it), but the only way to tell that would be to cut it open with a rock saw. (This would be a helpful thing to do, anyway.)


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