Personally, I've never had very good luck with these guys. I'm Exalted on two characters and all they'll ever give me is a handful of junk and some slightly better junk. I actually think the game is working against me when it comes to gems. I have the same luck with Prospecting. I know everyone says Prospecting is an amazing source of money, but I'm confident it only works for them because all of the awful gems are used up on me.
But enough QQ. Go! Get your gems! Make sure to leave comments lying about those Stars of Elune you got. It'll make me feel better if you just say you got a few Talasites.