What Does PT900 Mean on Jewelry?

PT900 means 90% pure platinum, with 'PT' being the element symbol and '900' the fineness. It's a common standard in Japanese platinum jewelry — a touch less pure than PT950 but still solid, hypoallergenic, and worth well more than most gold by weight.

What is a PT900 piece worth?

PT900 is 90% platinum — slightly less pure than PT950 but still heavy, durable, and valuable.

How to verify a PT900 stamp

Confirm the PT900 mark with the Hallmark Reader. Anyone can stamp a mark on metal, so a hallmark alone isn't proof — the fastest way to check is to photograph the stamp and run it through the free Hallmark Reader, then confirm the metal itself with the Is It Real? tool. For a full picture of what your piece is worth, get a free jewelry appraisal. To compare PT900 with every other mark side by side, see the full jewelry stamps and markings chart.

Frequently asked questions