Start your own rock collection and grow beautiful crystals! Learn and experiment with 8 different types of rock. Learn how to smash the toughest rock in the world! Comes with an instruction booklet to guide you through your experiments. Find a wide range of Poof-Slinky toys at Toys"R"Us.com! Poof-Slinky manufactures the POOF foam ball line and Slinky spring toys in the United States. Other products of POOF include the Classic Ideal construction toys and tabletop games, no-bake cooking kits, and science and activity kits. In the Spring of 2010 Poof-Slinky acquired Cadaco, a 75-year old manufacturer of a popular line of board games, including the famous Tripoley, the Ryan Oakes magic line, and the green activity/construction line EnviroBLOX; now called Stikits.