In the game,"Return to Krondor", it has display diamonds. You might need to change game engine, but some modder might be able to pull it off. You have look it up or play the game. I can't recall specifics, but this is the idea. It makes sense when it comes to gold and gems weight.
You can extend it from there. The gold exchange stays the same. The display shows how much gold in relation to gems and gold.
10541 gold displays as Flawless Diamond+Flawed Ruby+41 gold
The game also has a more fun and challenging trap system. I loved it!