The first one to be created by Dan, the Diamond Golem is, so far, the least powerful Golem. He helps protect Dan's house. He died when engaging a mob that overpowered him.
Quartz GolemEditThe second golem created by Dan, the Quartz Golem is stronger than the Diamond Golem, but not as strong as the Obsidian Golem. He has been poisoned twice and is at very low health. He engaged in combat (presumably) twice.