Rocks and Minerals Placemat by M. Ruskin Company helps a kids to know about different types of rocks: Igneous, metamorphic and sedimentary. Also helps to learn how to identify a mineral. It comes with Rectangular shape. It is brightly colored and laminated. From pre schoolers to grandparents there is a placemat for everyone. On the back of each placemat, learning exercises based on the front are given.