"Gems from other ores", that option makes it a little messy :(
I would like to have the option, to just get gemstone from washing.

What do you mean?

I mean that you can get spezial ores ONLY by washing stone, like your pictures describe and not from normal ores like:
Coal yields: Diamond
Quartz yields: Emerald and Amethyst
Bauxite yields: Ruby, Sapphire and Topaz

-> - Coal, Bauxite and Quartz have a probability of yielding a gemstone ("Gems from other ores" setting is hidden and forcibly locked on enabled)<-

alright, i'll add a setting for it then :D

Will a new savegame be needed or how long might it take?

Good enough? :D

Will a new savegame be needed or how long might it take?
It is savegame compatible, and it's already released

I will try it tonight, but it looks like a gg :)