I wouldn't be able to answer your questionnings...

Pigments and paint making : that's something I've always found intriguing, but too technical for me to approach efficiently with my empirical way of learning.

If art professions couldn't give answers, maybe getting in touch with chemistry ones would be another way to get your answer...

I've found this in French (deepl.com might help for a decent translation) : http://www.mediachimie.org/sites/default/files/chimie_art_129.pdf

I haven't read it, but it bored me so fast that I think it goes deeply enough on the topic :D

If you feel it has good infos but have a doubt on what you get with automated translations, I can give a hand for specific parts ;)