One of the four basic blocks (along with Dirt, Cave Background, and Lava), Rock is an unsplicable background which generates naturally in every new world, except for some blasted world. Fossils can also spawn on a placed Rock.
- 10 Rock Seeds can be obtained from the Basic Splicing Kit at the store.
- A Rock will morph into a Heartstone when a Love Potion #8 is used on it, which can be broken to obtain Valentine's Week items such as Angel Wings, Perfume, etc.
- Fossils may generate on Rocks in popular worlds/somewhat popular worlds.