From The Heroes of Might and Magic III wiki
Diamond Golem is a neutral creature that can only be recruited from Golem Factory founded on Adventure Map.
- Diamond golems can be very effective in the Dragogeddon tactic because of their spell damage resistance. While they will take damage from Armageddon, unlike for example Black Dragons, they will be unaffected by the Orb of Vulnerability. This has multiple advantages: Firstly it makes the Dragogeddon strategy resistant to an enemy player holding the Orb of Vulnerability, and secondly it allows Armageddon to kill creatures that would otherwise be immune to Armageddon if the player has the Orb of Vulnerability.