|Ruby and Fool's Ruby|
Biomes O' Plenty
Rubies can occasionally be found in Dungeon chests.
Fool's Ruby is a gem added by GregTech. It is visually identical to an actual Ruby, but Fool's Ruby components cannot be used in any recipes. Fool's Rubies can be differentiated from real Rubies by checking their metadata: the metadata value of all Fool's Ruby items are 10 higher than their real Ruby versions.
Ruby is currently not used, but it will be used in the future.