Yes, of course proustite is named after M Proust - just not that one.
Proustite is nothing to do with memory or madeleines. It's nothing to do with very long works of fiction, or people being remarkably French.
A proustite isn't someone who always says, well, of course they doesn't hold a candle to À la Recherche whenever you ask them if they enjoy whodunnits.
So that's a relief.
No, proustite is named after Joseph Louis Proust (1754 - 1826) a chemist, who identified proustite, aka silver arsenic sulphide in hexagonal cystalline form.
The stuff is sometimes called ruby silver, which is less confusing for everyone, as well as being a rather good title for a song.
Here it is:
It's remarkable stuff. But I can't help but feel sorry for M Proust the chemist, all the same.
Word Not To Use Today: proustite.