If as the poster says it doesn,t scratch with a screwdriver and a torch won,t melt it it,s obviously not aluminum regardless of what it looks like.I have no idea what it may be unless some exotic aircraft alloy,but that begs the question of how it was melted in the first place.If there is a scrap yard with one of those analysers,I think it uses a laser,near you they might do a test on it for you,otherwise I don,t know exactly what to do.If you do positively ID it please let us know,I,m dying to find out what it is.