From Granblue Fantasy Wiki
A piece of clay as rigid as stone.
Rough Stone is a normal quest treasure from Lumacie Archipelago.
|Buy various items from the Treasure shop||5-15|
|Upgrade Revenant Weapons (step 1)||100|
- All Free Quests on Lumacie Archipelago. Notable quests:
- Chapter 13 (39/52) Quest: The Fruit of Lumacie - 0-7 per quest, typically 3. (14 AP; also drops and .)
- Chapter 13 (39/52) Quest: Whiff of Danger - 2-4 per quest, always 2 unless Rare Monsters appear. (20 AP, characters only. High drop rate for Coarse Alluvium; Swirling Amber has the same drop rate as Rough Stone.)
- Chapter 15 Story - Forgotten Ruins - Part 3 - 0-7 per quest. (Also drops Swirling Amber and Coarse Alluvium.)
- Drop from Normal and Hard Yggdrasil raids (wooden chest)
- Cerulean Stone shop (3 for 5 stones)