I realized that.
My suggestion had a clan gem coffer where people could deposit but NO ONE could withdraw.
Clan leaders could authorize the gems be used for the av, or to CHANGE the av, but no one would be able to withdraw from the coffers into their own account.
It would be sort of like the Forehead Protector. Except that when you get to a certain amount, clan leaders could authorize clan extras.
I am not even certain that this solution would be possible as I have no knowledge to the inner workings of the LotGD code.
But I was absolutely NOT proposing that the gems could be withdrawn.
ETA: Also, my continued replies should not be considered as me lobbying for this particular idea. It may not be possible or attractive. I was just trying to come up with a solution for one potentially legitimate reason to pool gems. Again, no person could trade to another. In fact, if there were any gems in the clan coffers and a clan dissolved, a la <SK>, the gems would be lost - or go to charity.