* Roca: This is the most common translation for "rock" as a geological formation.
* Pedra: This is another word for rock, and it's often used in a more general sense. It can also mean "stone."
* Pedra-de-amolar: This translates to "whetstone," which is a type of rock used for sharpening tools.
* Rock (English): You can also use the English word "rock" in Portuguese, especially when referring to music genres like rock music or rock climbing.
The best translation for "rock" depends on the specific context.