This is a vintage Tataki. The gold part is, I was told at the time of purchase, K18. The blackening around the gold is tarnish on the silver. It will become clean if polished. The gold part does not change at all even if left untouched. The material of the entire Tataki is silver 925. It is a very beautiful pendant. As it is vintage, it is a one-of-a-kind item limited to the current item. Returns and exchanges cannot be accepted to prevent substitution. Immediate purchase is possible.