|Dropped by||(20%), (), , (, ), (), , (), (0.04% x3), Earthquake (5%)|
|Stacks up to||40|
Blue Gems can be used to turn Chester into Snow Chester by placing at least one in each of his inventory slots on a full moon. Snow Chester's special ability is preserving food longer like an Ice Box.
In Shipwrecked DLC, Fishing with Trawl Net in deep Ocean has a small chance to catch a blue gem. The chance is higher during Hurricane Season and Dry Season. Magma Piles found in Magma Fields also have a chance to drop Blue Gems when dug.
- The Blue Gem's element appears to be ice; its opposite being the Red Gem.
- When examined by most Characters, they will say something about the Blue Gem feeling cold, implying that it has chilling properties.
- Willow dislikes the Blue Gem most likely due to it being associated with ice and cold, the opposite of fire.