There is a size-3 card that says “Refine one mineral card for  points”
Does this mean 2 points per gem, or 2 points total?
It looks like it would be 2 points total, as the other refine cards specifically say " point per gem". However, that seems like an oddly underpowered ability for a size-3 card.
2 + blue boost total.
IIRC This is blue Refine from base game that can refine blue minerals. So it has an use.
This Refine even unboosted gives you mopre point tahn trade for 1 size card ( half the of the deck) is even break for 2-size and is worse for 3 size ( 1/6 of the deck) so have weighed advantage of 1/2-1/6=1/3 VP over a Trading an average card. If boosted it is very good action to dump 1 size minerals in colors with odd sum. it is 3VP for one mineral card of any color - other Refines are very specific.