In order to purchase it the player needs to have completed before patch 6.0.2.
Patches and hotfixes
- Patch 6.0.2 (2014-10-14): No longer a quest rewards.
- Hotfix (2013-01-08): "Commander Oxheart in Townlong Steppes will now sell Crystallized Dread, Crystallized Terror, Crystallized Horror, and Eye of the Black Prince for gold to players that have completed the appropriate quest lines."
- Hotfix (2012-11-06): "Tooltips for Crystallized Dread, Crystallized Horror, and Crystallized Terror have been updated."
- Patch 5.0.4 (2012-08-28): Added.