Are normal rocks healthy for goldfish?

Normal rocks are generally safe for goldfish to have in their tank as long as they are smooth and free of any sharp edges that could injure the fish. However, rocks can also introduce harmful bacteria into the tank, so it is important to thoroughly clean and disinfect any rocks before adding them to the tank. Additionally, some types of rocks may affect the water chemistry in the tank, so it is important to research the composition of the rocks before adding them to ensure that they are safe for goldfish.