On Rainbow Island, Slime Rancher 2 is filled with various types of slime for you to find. Rock Slimes are well-hidden and will take some time to find.
Rock Slime location in Slime Rancher 2
The Ember Valley area is located to the northwest of the Rainbow Fields. To unlock Ember Valley, you must remove the pillars that are blocking the teleportation pad to the area. After reaching the area, go west and then north.
Rock Slimes may be found in many locations around Ember Valley, but most commonly they are found in caves. This is also where you can find Crystal and Batty Slimes. When a Rock Slime starts rolling, it will likely hit you very swiftly.
How to care for Rock Slimes
Rock Slimes prefer to stick to an all-vegetable diet. In other words, make sure to have plenty of Carrots and Water Lettuce around to keep them satisfied. This will prevent the Rock Slimes from falling out when they roll at the side walls. Without the upgrade, they will easily fall out and run around the conservatory.