Ruby

 is a raw material used in forging weapons. It is also a universally liked gift.

Obtaining
can be obtained as a rare drop by harvesting a Crystella tree.

can also be rarely obtained by quarrying rocks by the lake in the Collapsed Wasteland.

Usage
can be used for upgrading swords. It can also be gifted.

Forge
4 Rubies are required for revising any sword to Rogue Knight's Sword's attributes using the Forge.

Gift
can be given as a gift to other characters. It is a universally liked gift.