These collection items can only be obtained from Buried Treasure.
If completed with 3 other collections (Rare Oval Gems, Treasure Hunter Masks, Antique Weapons), you can complete the top-level collection: Master Treasure Hunter.
Treasure Hunting
- A rare red trilliant gem
- A rare green trilliant gem
- A rare blue trilliant gem (possibly the rare piece of the set)
- A rare yellow trilliant gem
Reward: A medium amount of XP.
NOTE: If you're searching for these on the bazaar, it's spelled 'TRILIANT"