The ring I bought said JMZ PT990J. Is it platinum? Why is there a J behind PT990? I mainly want to ask why there is a J in the back.
JMZ, it's short for brand. This ring of yours is real platinum, you just need to find the PT logo, and there is color behind it, 990/950/900. The j at the back may be the code name of a factory. In order to ensure the quality, any factory with problems can easily find the reasons. Generally, only big brands will have this trick, like Hong Kong Golden Supreme Jewelry.