Obsidian

This rarely used boys name is one of the few gem names for a boy. Obsidian is actually a type of volcanic glass, formed when lava cools very quickly. This ultra-cool name might spark a love of volcanoes and geology in a little boy.

Pronounced ob-SID-ee-un.

As of October 2026, Obsidian ranked #5778 for boys in US births in 2025 SSA, peaked at #5005 for boys in 2023.