Granite Cave

Desktop/Console/Mobile-Only Content: This information applies only to the Desktop, Console, and Mobile versions of Terraria.

The Granite Cave is a mini-biome found in the Underground and Cavern layers. Granite Caves are generally wide-open caverns dotted with occasional ledges, though their shape may vary due to the presence of overlapping cave systems. They are made entirely out of Granite Blocks and Granite Walls and contain several Pots. Underground Cabins spawned in a Granite Cave will be made out of Granite-themed blocks and furniture.

Notes

Since it is only a mini-biome, the usual NPC spawning rules do not apply to the Granite Cave. Instead, Granite Elementals and Granite Golems require one Granite Block on which they can spawn, inside the player's spawn range; or any Granite Block between 30 and 60 tiles away from the player. A single Granite Block is sufficient (although the chance increases with the number of Granite Blocks) and Granite Walls do not have any impact. However, if the player is standing on a Granite Block, the chance for Granite Elementals and Granite Golems to spawn gets a significant boost. In that case, no further Granite Blocks in the vicinity are required.^[1]
In drunk worlds, the generation structure of Granite Caves is swapped with Marble Caves.

Granite biomes usually have at least a standalone chest in them, so once a player is powerful enough to repel Granite Elementals, they should explore the biome.

Desktop 1.4.0.1:
- Added new Granite rubble piles.
- Added two new drops from Granite Cave enemies:
  - Both the Granite Elemental and Granite Golem have a 5% chance of dropping the Geode, a consumable which will drop two types of Gems upon being thrown, and a 2% chance of dropping the new Spaghetti food item.
- Fixed a world generation issue where Granite and Marble biomes that had generated under the Dungeon would still leave some of the Dungeon Bricks hammered in the same shape they were when before the Dungeon generated.

↑ Information taken from the Desktop 1.3.5.3 source code, method SpawnNPC() in Terraria.NPC.cs. There may be inaccuracies, as the current Desktop version is 1.4.4.9.