Diacitrine

"Diacitrine is the cortex of voice and truthfulness. This stone is in the Voidfell, embedded in a hammer held by Alric Gravelmane, king of the Titanium Dreadhalls and the Dominus Empire. Getting it is supposed to be what kills my friend, Erithien Darkmoon. She doesn't seem bothered by dying. But I am... for her though. I would miss her if she died." - from the journals of Feye Lyne