in my attempt to get a full set of lambent back in the day i slaughtered griffenes for hours and hours. never once got a griffene charm. also screw that bracer, buy a pair of either of these:
http://wiki.project1999.com/Kylong_Wrist_Guards
http://wiki.project1999.com/Sebilite_Scale_Bracelet
cheaper than lambent and better stats with less weight