can anyone tell me what this is.

[LONEWOLF]

May-be, just may-be, Martin and I might be on to something. :Y: ... If more was around this would dispel our 'Theory'..... IMO... Dam I've run out of Popcorn.. 8)

LoneWolf....

 

[Gilly47]

I see you mentioned Blue stone. What significance does bluestone have in geology please???

 

[nev]

A real wild stab in the dark here
Could it be slag from a coal fired boiler
The green being corrosion