What Does PLAT Mean on Jewelry?

PLAT — or the full word PLATINUM — stamped on jewelry means the piece is solid platinum. It's usually paired with a fineness number such as 950 or 900 to show the exact purity. Platinum is rarer and denser than gold, naturally white, and hypoallergenic, which is why platinum jewelry is prized for engagement and wedding pieces.

What is a PLAT piece worth?

A PLAT mark signals solid platinum — dense, durable, naturally white, and usually worth more than gold by weight.

How to verify a PLAT stamp

Look for a purity number alongside PLAT (like 950); scan the full 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 PLAT with every other mark side by side, see the full jewelry stamps and markings chart.

Frequently asked questions