We have a guild bank with 8 144 slot tabs. Most of us are pack rats, so we pick up every skill gem that drops and then stick it in the bank if we don't want it ourselves. Which resulted in a bank full of absolute trash with a couple of potentially useful gems mixed in for good measure. I wanted to clear it up, but wasn't really sure how. I cleaned up the currency tab earlier by sorting it according to market value at that time but doing that for gems is a lot trickier. For one thing, most gems are worth nothing at all. For another, gems don't stack. Which makes it really hard to know if a given gem that dropped is 16th in value, or 142nd, or whatever if we didn't already have one. And if we did already have one we probably didn't want any more of them. Certainly not if it was an easy to quest for gem.
My first try was to sort the gems by colour, type, and then alphabetically. All the auras on top, then all the skills, then all the support gems. This worked reasonably enough, but other people didn't seem too interested in figuring it out when adding new gems so they just shoved all incoming gems off to the side. That's still an improvement over what we had before! I went through the mass of incoming gems again yesterday to resort and decided I wanted a better way to know what stuff I wanted to store extra copies and which stuff I could just vendor all but one copy. (Maybe someone really wants fireball RIGHT NOW, or maybe people eventually want to see a list of all gems?)
I ended up taking my spread sheet of gem slots and colouring it based on first quest. If the gem is found in act 1 of normal it gets coloured green and I vendor all but one copy that shows up. If the gem is found in act 2 or 3 of normal it gets coloured yellow and I vendor all but two copies. If the gem is found in act 1 cruel I coloured it red and keep at least 3 copies. Sceadeau also found me a list of really valuable gems and I bolded those ones to make it easier to know at a glance which ones to really keep extras for.
Maybe having these spreadsheet screenshots somewhere will help other people know how easy a gem is to quest and which ones we really need? It looks like elemental hit is fairly easy to get but we don't have any yet!