I got about 10 different kinds of gems and don't know what to do with them but to sell them, is there any real purpose to gems other than making money?

Nope, unless you find a better purpose, in which I haven't, and I beat the game 2 times. Nothing but selling them.

It's not like BGII, where you can use them to make more powerful items, it's like in BGI where they're just there to make it more picturesque. I mean, what's the fun in just finding gold all the time?

Does money have a purpose?

In some cases if you review the AD&D First Edition rules, some spells required the use of components (roots, berries, leaves, etc). I would have to pull out my ragged Players Handbook, but I would almost bet that there were some spells that required the use of a gem as a component. I know that some of the artifacts from the First Edition game had gems used in them (ie Gem Encrusted Dagger). But from what I can tell, the only thing you need here is casting time. Unless, of course, BI is going to put them to use at some point in a future expansion module.

At this point, I give them all to my cleric who has the best charisma and she sells them for the party.

Lord Teppenwolfe