Crayon Rocks are soy-wax crayons. They are free from petroleum or animal products. Their rock shape helps young kids develop their tripod grip (for writing). They are smooth and soft and go onto paper or fabric beautifully easily. Since a child's first writing tool is usually a crayon, that crayon should be one that encourages him or her to use thumb, first and second fingers in a tripod grip. Crayon Rocks' shape doesn't allow you to hold in a fist or other grip that deters fine motor development. What it contains: A muslin cotton bag with... 8 crayon rocks: red, green, blue, yellow, black, brown, orange, purple 16 crayon rocks: red, green, blue, yellow, black, brown, orange, purple, pink, grass green, sky blue, sunshine yellow, gray, tan, peach 32 crayon rocks: As for 16 colours plus gold, silver, turquoise and more earth colors including skin and hair colours for drawing people