Opal is a kind of opal whose color reaches the gem level, but none of the opals in China reach the gem level. So China doesn't lay white stones. The best opal comes from Australia. There are not many merchants selling opal in China, but there is an Australian opal with high cost performance. Moreover, Opal is all Australian Opal. If you buy Opal yourself, you still need to find a trustworthy merchant, because there are cases in the market where African Opal impersonates Australian Opal. So I suggest you go to Opal, Australia.