1 slot reward is evaluated according to whether the colors of the gemstone and the slot correspond. If you don't need the slot reward attribute, you can set the gem you want to insert regardless of the slot color.

The jewelry supplier next to Dalaran Jewelry Trainer can exchange the jeweler's brand for daily tasks, or exchange 10 Titan iron powder for a jeweler's brand, and then exchange the jeweler's brand for special gems.

If you have drawings, you can take your own drawings or some drawings of some best-selling gems first.