Gem Trader is a Merchant NPC.
He'll trade 5 of one grade gem to 1 of the next best grade. However, there is a gold fee for each gem, and it accumulates if you exchange more gems at a time. The fee for each gem stays the same regardless of what grade you're trying to get.
| Gem | Price per exchange |
|---|---|
| Tigerseye | 100 |
| Agate | 100 |
| Citrine | 140 |
| Amethyst | 180 |
| Obsidian | 220 |
| Turquoise | 260 |
| Olivine | 300 |
| Opal | 340 |
| Spinel | 380 |
| Aquamarine | 420 |
| Moonstone | 460 |
| Ruby | 500 |