John Faithfull 🌍🇪🇺🏴󠁧󠁢󠁳󠁣󠁴󠁿🧡✊🏻✊🏿 on Nostr: I think the ultramarine referred to here may be cobalt blue (although this was often ...

I think the ultramarine referred to here may be cobalt blue (although this was often called smalt in former times). "mundic" was a term for pyrite and other hard sulfides/arsenides - cobaltite/smaltite inlcuded. These occur in some Cornish mines, and were worked I think, probably to produce cobalt blue. Must check...