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I found this rock on the edges of a known Drumlin in North East England. It looks to be a fragment from a larger piece. It attracts a magnet strongly, it weighs 150 grams. It has vesicular holes (on what would have been the surface) with round beads of metal inside some of them. It looks crystalline in structure and has small shiny inclusions. It also looks like it has a layer section. All very confusing. Any idea what it could be?

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closed as off-topic by Gimelist, trond hansen, Universal_learner, Fred, Peter Jansson Aug 9 at 13:09

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    $\begingroup$ Picture 2 shows one of the vesicular holes in detail, it shows small spherical beads stuck to the walls of the hole. $\endgroup$ – Andrew Howe Jul 22 '18 at 10:49
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    $\begingroup$ All sides look the same colour, it looks to have been weathered. There "may" be a crust to the face with the holes but it is not clear or black. I cannot add more than 8 pictures according to the system. $\endgroup$ – Andrew Howe Jul 22 '18 at 11:08
  • $\begingroup$ I think you weren't lucky. From this post a meteorite can't be magnetic and have vesicles. earthscience.stackexchange.com/questions/7797/… $\endgroup$ – Universal_learner Jul 22 '18 at 22:50
  • $\begingroup$ The linear patterns could be Widmannstatten structure often found in high iron meteorites , which matches up with the ferromagnetic properties. $\endgroup$ – blacksmith37 Jul 23 '18 at 0:48
  • $\begingroup$ The vesicles, to me, have been the reason for doubt over it being meteorite. However, there are examples (Toluca Iron Meteorites) that show these holes on the surface. I'm not sure how to class these holes, vesicles is what they look like. I guess a lab test would be the direction I should go with this specimen. $\endgroup$ – Andrew Howe Jul 23 '18 at 8:54
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This texture is not Widmanstätten, which only becomes visible after polishing and etching. And it doesn't like like it anyway. Meteorites also don't have bubbles (at least not that big and rounded). Therefore, this is not a meteorite.

It also looks very much like a komatiite, but these rocks are not found in England. Komatiites form by fast crystallisation of very hot depolymerised silicate melt, which leads us to what it really is: Slag. Slag can sometimes be very hot depolymerised silicate artificial melt. Iron and steel production was very common in north east England, so this is the most likely explanation. Slag.

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If the rock did not have the vesicles, I would say it is a komatiite as was suggested above. Because the vesicles are present, I agree with slag. The texture observed in the rock is called "spinifex" texture which is an irregular arrangement of tabular and acicular crystals, common in slag. https://www.researchgate.net/publication/279718297_Metallurgical_slags_with_spinifex_textures

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