Anguish Gemstone

There are four types of Anguish Gemstones:
 * Margonite Gemstone
 * Stygian Gemstone
 * Titan Gemstone
 * Torment Gemstone

Acquisition
They drop rarely as loot from the monsters in the Domain of Anguish. One gem of each type is also available as part of the reward for completing the Mallyx the Unyielding quest.

Uses

 * Four Anguish Gemstones (one of each type) can be traded to the Keeper of Secrets in Gate of Anguish for a Coffer of Whispers.
 * 60 Anguish Gemstones (15 of each type) can be traded to any Spirit of Truth for an Armbrace of Truth, which can be traded to the Deacon of Whispers for a gold tormented item.