Topic: Vasart / Strathearn transition UV

[Frank]

UV fluorescence is an extremely complicated subject...  ...but can also be affected by the annealing process, and the furnace gases
Alan

With a distinct change from one week to the next, from town to propane gas and I assume they got a new annealing oven too - there is thus a slight possibility for further thoughts on this. 

[KevinH]

The main characterstic of UV fluoresence for Scottish weights is whether it shows as blue or not. If it does, then it is very likely that the batch contained sufficient lead to give that UV reaction.

I doubt whether change of gas type or the annealing process would have a marked affect on the UV colour reaction beyond chaning the intensity or clarity of the basic colour. But if somebody could come up with some definitive comments, with photos, that show what sort of change can occur with differing gas types or annealing controls, I'd be very interested.