These stones are made of wood.Stacking Stones - 36 Pieces$29.99PriceQuantityAdd to CartAge:3 years and up Benefits: Aids in the development of hand-eye coordination Aids in the development of fine motor skills Disclaimer: This is an educational product and is only to be used under adult supervision, owing to properties essential to its purpose. This product may contain plastics packaging which must be removed and kept away from children.