OneGuyFromBarlick

Is it kids Play Dough... or the like?

Not ambergris and not highly magnified. Nor is it play dough or similar. Keep thinking!

Looks like cabbage

Looks like a bright green foetus. Sigourney Weaver - Aliens - extracted from her abdomen?

The head of some kind of soft structured creature that has undergone some process akin to fossilization. Why is it green? the colour of the preservative maybe.

Hulk snot?

Knowing Peter's interest in the subject I suspect it's a geological sample. Something very rare!

Well in that case I think it’s something to do with Jade.
Molten Jade... is there such a thing?

Not a foetus, cabbage, snot, fossil, geological sample or jade. Time for a clue - looking back I see that I inadvertently dropped a clue in the first paragraph of my post that contains the image!

Whoops! Mrs Tiz has just pointed out that Cathy didn't just write jade, but `molten jade'. It isn't jade but she's spot on with the `molten'. Sorry about that Cathy!

In that case, Molten Hulk Snot for stemming holes drilled for explosives!

Wax impression of your lughole for fitting a hearing aid?

That sounds feasible China, I like it!

A plastic explosive ?
Or packing for one.

That's a possibility Cathy but all the plastic explosive I have ever seen or used wasn't green. C4 and 808 are both a tawny brown.

Is it Lord Percys nugget of purest “green”?
Or
Is it the result of a bomb blast, hydrogen bomb maybe?

Anything produced biologically by Shrek?

Is it the last remnants of a bar of Fairy laundry soap?

This is great fun - you're all very imaginative - but all wrong....except for Gloria (she's good at this game, isn't she? ). No, it's not `Lord Percys nugget' but she's spot on with `result of a bomb blast'. To be more specific it was melted either during a bomb blast or due to an incendiary bomb. But it's not just any old bit of melted stuff, I want to know what it was before it was melted. It might look like just a green blob but it has interesting history!

Trinitite after the Trinity bomb blast?

No, Gloria. It was something domestic and linked to a particular era.

Pompei and the product of melted sand or other material?

WW2 'blitz'? Is it part of a window from a church or cathedral?

WW2 'blitz' is correct but not part of a window from a church or cathedral.
Ian, not Pompei but `product of melted sand' is right! But what is the identity of that product?

Wine bottle?