From Stardew Valley Wiki
|An extremely dense piece of stone.|
|Source:||The Farm • The Mines • Skull Cavern|
Boulders can be harvested by a steel pickaxe and above tiers.
Every type of boulder yields 10 stones.
The Boulders in the mines can be harvested using at least a copper pickaxe.
Boulders that can be found in the Mines levels 41-79.