Valuable gems

[BloodBlade22]

Hi there everyone!

Its been a long time since I played this game, and was just wondering if there are any quest related gems, or if its all just vendor trash? I seem to remember something like kings tears or whatever being useful, but then again its been like 5 years since I last played.

Thanks.

P.S. I didnt want to post a new thread on this because its probably been answered a million times. Sorry in advance. Im playing a kensai/mage build, and was wondering- with the new expansion- what is the best level to dual-class to mage. Ive heard 9, 12, 13, so im a bit confused which is best, and if they are refering to BG2 or TB.

Thanks again!