So I think anyone with a pickaxe has noticed that gems are (strangely) glitched a bit for now, in very specific ways.
If you try to sell or donate them to a shop it will give you money in the shop window but not in the main one but not remove the item from your inventory. However if you refresh the item vanishes and you get no currants. I am dubbing these "phantom gems". Basically I don't think they're really there.
BUT I have noticed something interesting. Not all gems are phantom gems. If you refresh, and the gem survives in your inventory, it is "real" and seems to be sell-able (or donate-able if you rather). It does take the game a moment to process but it vanishes and the currants appear.
...At least, they did today. Here's hoping. Good luck!