Re: Mmmmmm, Soulglazed Relics - Gamer Escape's Final Fantasy XIV (FFXIV, FF14) wiki

You need to have talked to the NPC (Jalzahn) to 'Soulglaze' your relic. He needs to apply something to it so that it can receive light. I forget which dialogue option it is, but it'll be one of the available ones when you interact with him