Signing: The rock sign looks a lot like clanking two rocks together. To sign rock, make both hands into a fist. Then you bump your strong hand into the back of your weak hand.
Usage: Make the rock sign when you are outside and your baby picks up a rock.
Flash Card: Click the link to view the Rock Baby Sign Language Flash Card. The flash cards are printable and available in both U.S. Letter and A4 sizes.