- Quest reward
- The Stygian Chest that appears after killing the Dreadspawn Maw contains 1–4 Stygian Gemstones for each party member, one for each of the Lords of Anguish which have been defeated during the current trip through the Domain of Anguish. This amount is doubled in hard mode, allowing up to eight gemstones to drop.
- A Coffer of Whispers has a chance of giving you 5 Stygian Gemstones.
- 4 Anguish Gemstones (one of each type) can be traded to the Keeper of Whispers in Gate of Anguish for a Coffer of Whispers.
- 60 Anguish Gemstones (15 of each type) can be traded to the Spirit of Truth for an Armbrace of Truth, which can be traded to the Deacon of Whispers for a gold tormented weapon.
This stone has the same appearance as a Stone of the Elements.