Pristine Black Diamond

Pristine Black Diamond is a rare raw gem.

Source
Pristine Black Diamond drops off high-level Elite mobs throughout the world and in instances.

It is primarily found in Stratholme. Other locations that have a lower drop percentile are Dire Maul, Blackwing Lair, and Blackrock Spire.

Other information
Formerly, the primary demand for this item came from players who attemped to complete the achievement, which among other things required a character turn in about 84 librams of Focus, Protection and Rapidity for Shen'dralar reputation.

Jewelcrafting

 * Figurine - Black Diamond Crab

As a quest objective

 * Libram of Focus (quest)
 * Libram of Protection (quest)
 * Libram of Rapidity (quest)
 * Material Assistance
 * The Divination Scryer
 * True Masters of the Light (2)