Yes, it is an interesting question.
The world "sulphide", relating to an incrustation in paperweights (and other glass items), was not used in Apsley Pellatt's 1849 book
Curiosities of Glassmaking. And it was also not used in Harry Powell's
Glass-Making In England, published in 1923.
It was certainly used by Mrs Bergstrom in her 1940 book,
Old Glass Paperweights.
And it was also used in 1948, in the English translation section of
Les Presse-Papiers Français De Crystal by R. Imbert & Y. Amic. In the section for "Origin and First Manufacture of Paperweights", the English version gives, in part:
The Cruesot … the making of “incrusted cameos” or “sulphides”.
So I wondered whether that implied the French had always used the term "sulphide" [but, of course using "sulfure" in their own language]. If that was true, then perhaps the word has its first usage in French many years before the 1940s and was simply translated as "sulphide". However, the French text for that same reference gives:
La Cristallerrie de Cruesot ... la fabrication de des « medailles » ou « camées incrustés dans le cristal » que le commerce de la curiosité désigne de nos jours souse le nom de sulfure.
And although I do not have the skill to properly translate French, it seems that "sulfure" in that context was referred to as being "used nowadays". If that is correct, then it does not really help in the quest for the first use of "sulphide".
But perhaps there is some earlier French, or even English language, literature that describes "incrustations" as "sulfures / sulphides"?