Re: ultramarine blue

[Alberto Novo <alt.list@albertonovo.it>]

> ...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. 
Alberto