GURPS Magic - Creating gemstones

[malloyd]

Originally Posted by Anders

I think the purpose is to keep people from creating a lot of valuable material and short-circuit any adventure where there's a reward. If you can create a cubic yard of diamonds then the economy will very quickly be broken.

Yeah, it's mostly a patch on one of the more obvious ways creation spells mess with the concept of "valuable", but there is an important secondary issue in GURPS in that the high cost of large gems is one of the important limits on the proliferation of large Powerstones, which break a different economy and hence have several other kinds of strange seeming limits.

The fact that magic treats the value of gemstones as something special with respect to Powerstones actually helps to justify it treating it as something special with respect to Earth spells too.