Go stones Set of 10 5 white, 5 black Material: I think it's probably plastic. I apologize if I'm mistaken. Size (cm) White: Diameter 2.14, Thickness 0.72 Black: Diameter 2.16, Thickness 0.71 These are average values, so there may be individual differences. Please forgive any errors due to amateur measurement. Please note that the color of the actual product may differ slightly from the photos depending on your smartphone or other device. These are used items, so they may include minor scratches, light stains, and signs of use, but there is no significant damage. Therefore, the condition of the product is rated as "no noticeable scratches or stains." I have checked carefully, but please forgive any oversights or omissions in the photos due to amateur inspection. Please consider purchasing only if you understand and agree with the product description.