Where to Farm Arcane Crystal

The best place to farm Arcane Crystal is Zul'Gurub, where Hakkari Thorium Vein is mined for it at 5.8%. That is the vanilla 1.12 chance, not yet confirmed in Forever. 3 sources are ranked below by drop chance.

Best zones:

Zone	Sources	Best source	Level	Drop%
Zul'Gurub	1	Hakkari Thorium Vein		5.8%
Winterspring	1	Rich Thorium Vein		2.9%
Silithus	1	Ooze Covered Rich Thorium Vein		2.9%

All sources, by drop chance:

Vanilla reference — from the 1.12 world data, not yet confirmed in Forever.

Source	Level	Zone	Spawns	Side	How	Drop%	Map
Hakkari Thorium Vein		Zul'Gurub	15		Mining	5.8%	map
Rich Thorium Vein		Winterspring	199		Mining	2.9%	map
Ooze Covered Rich Thorium Vein		Silithus	69		Mining	2.9%	map

Needed for:

Quests:

Level	Quest	Needs
60	Belt of Faith	2x
60	Bindings of Faith
60	Cap of the Scarlet Savant	8x
60	Dreamwalker Wristguards
60	Frostfire Belt	2x
60	Frostfire Bindings
60	Plagueheart Belt	2x
60	Plagueheart Bindings
60	The Dread Citadel - Naxxramas	5x
60	The Dread Citadel - Naxxramas	2x

Recipes:

Recipe	Profession	Needs
Enchant 2H Weapon - Strength	Enchanting	4x
Obsidian Scope	Engineering	1x
Transmute: Arcanite	Alchemy	1x

Drop% is the rate recorded in Forever once a source has been looted ten times; a greyed figure is the vanilla 1.12 chance from the world data (vanilla reference — from the 1.12 world data, not yet confirmed in forever). Spawns counts the source's spawn points in the world data. "Side" names which side can kill the NPC when the other finds it friendly. The lead picks the best chance among sources that are not a rare spawn and have at least three spawn points.