Items, NPCs, quests, objects and spells of patch 1.12.1, read live from the realm itself.

Magma Forged Band

NPC Level Zone Chance

Watchman Doomgrip Elite 55 0.223%

Warbringer Construct Elite 53 - 54 Blackrock Depths 0.021%
Object Zone Chance

Dark Coffer Blackrock Depths 0.2%

Secret Safe Blackrock Depths 25.0%
Item Count Chance

Large Brilliant Shard 1 100%

NPC	Level	Zone	Chance
Watchman Doomgrip Elite	55		0.223%
Warbringer Construct Elite	53 - 54	Blackrock Depths	0.021%

Object	Zone	Chance
Dark Coffer	Blackrock Depths	0.2%
Secret Safe	Blackrock Depths	25.0%