Just an Idea for gems after lvl 50.
Gem combinations example Opal,onyx,diamond or amber,ruby. the gem value would be split by the nuber of gems in combination. seeing as they don't drop this would raise value of cracked gems as higher grades of combination gems would only be able to be fused with others of same combos. this can also open up a new drop item to farm in order to combine gems and still use normal fusion powder to upgrade. this idea would also open up new builds and battle strategy based on builds, new multi classes.