The Obsidian Fire Pit is exclusive to the Shipwrecked DLC and the Obsidian version of the normal Fire Pit. It requires 3 Logs and 8 Obsidian to craft, and an Alchemy Engine to prototype. It allows Fuel to last 3 times as long as a Campfire and 1.5 times as long as a Fire Pit, while also emitting a massive light radius, making this the most effective and resource-friendly fire. Obsidian Fire Pit doesn't set surrounding objects on Fire (unlike the Campfire)
The Obsidian Fire Pit is immune to being extinguished by Strong Winds, but can be flooded. The Ice Flingomatic can still extinguish the Obsidian Fire Pit if within range.