The quest The Brink of Extinction must be completed. And higher combat stats are recommended.
It may take 10 hours or longer to get the helm.
Obsidian shards are items dropped by the TokHaarmonsters within the Fight Cauldron, which is accessible after completion of The Brink of Extinction. The shards are a guaranteed drop, in quantities ranging from 1 to 7, from the TokHaar monsters, with stronger monsters generally dropping more shards at once. The shards can be somewhat hard to see on the floor, so it is advised to use the minimap to more easily locate them.
With 80 Smithing, players may smelt obsidian shards into obsidian bars at any furnace; 12 shards are needed to produce 1 bar. This grants 50 Smithing experience per bar. The bars may then be used at an anvil to smith obsidian armour, powerful high-level armour that is exceptionally useful against TzHaarand TokHaar monsters. However, outside of the TzHaar areas this armour increases damage received.