Simply put to upgrade this gem you must already have it and all the gem food required for the upgrade and or needed gems
so if (8-9) you need a rank 3 and 2 rank 5s you need ALL the food to make them from a rank 1 or a corresponding gem.
Go to Jeweler and upgrade the gem, it will offer you the needed duplicates at 4 pearls each.
IF this option does not appear and it says you need to Craft/Elder/Buy the gem then you do not have enough gem food!
You CAN NOT do partial upgrades anymore, you either upgrade a gem a full level or nothing (either the main or if u have a duplicate).
They said it would be harder to upgrade and by that it looks like they meant having everything needed at one time. Hopefully this help explains things.
