Clearly Made of Resin [SEP] Although this product works well to cool my under-eyes, I was pretty disappointed with the quality. There is a black dot baked into the large roller that could not be removed with water or scratching at it. There are several bubbles in the small tool. More flaws can be seen with the naked eye rather than in the pictures (I tried). I was mostly disappointed because I thought that they were sending me a product made of pretty stone, and these are clearly not stone & are most likely some sort of resin. The small roller does not roll very easily, but I could have looked past that. I hope this was helpful.