Re: ultramarine blue
...If ultramarine is sodium aluminum sulfosilicate, is it possible, chemists on the list, that the acidity of the gum would be responsible for releasing this smell? I do have a hyper sensitive nose, I have been told.In principle, yes. Our nose is very sensible to sulphidric acid (H2S), so it is enough that only a minimum amount be released.
I have never used ultramarine blue for gum, but I have prepared a lot of resinotype powder. This is made heatingh toegether rosin and pigment up to about 100-120°C. Rosin is about 90% abietic acid, and a little sulphide smell is noticeable also in this case.