There are two kinds of Jedi Relic.
This yellow colored collection item can be looted (or stolen by spies) from various force user NPCs around the galaxy, mainly from Dathomir Nightsisters.
A Jedi needs to combine 10 of these relics to complete the One-handed Fifth Generation Lightsaber collection, required itself for the Master Jedi Cloak collection.
- A Dark Adept - Dantooine (13 April 2011)
The blue version can be created with the Chu-Gon Dar Cube or looted through the Rare Loot System.