[DenStoreFrelser]

If possible, I think the best way to deal with the gem-creating items would be to put a limit of ten or so of each item per nation or game. Basically just adding a few lines of code to the clams and other items, so that before they create a gem they check an integer value, if it is not below the maximum number nothing happens, otherwise it is increased by one and the item does what it usually does. (My programming knowledge is limited to a bit of Java, so this probably won't be as simple as I think, but I like to pretend that I know stuff.)

A thematic reason to add a limit to the amount of gem generating items could be that they absorb ambient magical energy from the world like the arcane nexus spell, and that there's a limit to how much of this it is possible to capture in a single month.

Hadrian_II has a point about this issue "balancing" with how blood nations can get more magical resources than the others, but isn't blood hunting pretty useless in provinces with high unrest? I think it's easier to damage blood income than it is to take out hordes of clam carrying researchers hiding beneath two or three domes and an army.