Strange green swirlly plastic like rock?

[Togalosh]

Hello,

Geography..does this stretch to including geology too? (..it's not exactly wild)


I've been finding & uptil now ignoring this dark & light green swirly almost plastic like 'rock' on my allotment thinking it was just some buried rubbish.

When it's been mixed up and put on a bonfire & fizzes, whistles & goes off like chinese fire crackers. It comes in quite big lumps.

Any ideas...or should I just find a geology forum?

[Jim Ford]

Sounds like malachite. Didn't think we had it in Britain:

Malachite - Wikipedia, the free encyclopedia

If it is and you get the bonfire hot enough, check for copper in the ashes.

Jim

[Cotham Marble]

Originally Posted by Togalosh

Hello,

Geography..does this stretch to including geology too? (..it's not exactly wild)


I've been finding & uptil now ignoring this dark & light green swirly almost plastic like 'rock' on my allotment thinking it was just some buried rubbish.

When it's been mixed up and put on a bonfire & fizzes, whistles & goes off like chinese fire crackers. It comes in quite big lumps.

Any ideas...or should I just find a geology forum?

Photo would help but doesn't sound geolgical; some kind of furnace waste would be my guess. Possibly metal or glass making slag, though I would not have expected that to give any pyrotechnic performance.

CM

[The Woodman]

It does sound like some sort of industrial waste or residue. I would steer clear of the bonfire smoke just in case there are any nasties being released to the atmoshere - thinking about it - I wouldn't put it on the bonfire.

[healfdan]

As it was found in your allotment the chances are that it was a plastic or polythene container that has been melted and reconstituted by heat.
Could have previously contained fertilisers or garden compounds which would account for the sparks. The hissing and fizzing is due to moisture trapped within the object.

[Cotham Marble]

Originally Posted by healfdan

As it was found in your allotment the chances are that it was a plastic or polythene container that has been melted and reconstituted by heat.
Could have previously contained fertilisers or garden compounds which would account for the sparks. The hissing and fizzing is due to moisture trapped within the object.

The OP says "it comes in quite big lumps", and also says 'it whistles' - which could be moisture escaping but equally could be heated gasses trapped in voids in the material - small stones will do this on a very hot fire. Many older allotment sites had cinder paths made up of various industrial furnace wastes and slags. From the description given, glass making slag seems the most likely candidate - which makes it very 'not smart' to put it in a fire - having sherds of glass slag flying around is not healthy.

CM

[Togalosh]

Thanks for the help & advice so far & sorry for asking a question without taking a photo - but it was a spur of the moment question.

I've collected some today but did not have chance to get a pic of them in daylight (to get the proper colours) so I'll be taking pics in the morning.

. ..but I am sure that they are not plastic (they are too heavy, sound like rocks when chinked together, cold to the touch & form part of a rock that is not visually the same) and it's not green with copper verdegris.

..but what is really trippy is that when I tried to split one apart with a hammer to show the rough whitish outer & coloured inner it gave off a very strong smell of pig slurry ! The stink went away soon after.

I couldn't make this up if I tried. Pics to follow tomorrow.

[Togalosh]

..oh yes..also there's lots of volcanic type rock around too (big enough & in large enough quantities to build very big walls nearby)..again I'm guessing it's volcanic as it is glassy & has air/bubble holes in it...either that or we have the toughest earthworms ever.

[Deb London]

I can't wait to see this rock.

[Johnny Redgate]

Sounds like a couple of types of foundry slag - green/blue glassy stuff and cinder/clinker type material made into blocks for building. I've seen walls made out of this type of stuff in the Black Country.