What Does PT950 Mean on a Ring?

PT950 is a fineness mark: Pt is the chemical symbol for platinum, and 950 states the purity in parts per thousand. A PT950 ring is 95% platinum by weight, with the remaining 5% typically ruthenium, iridium, or cobalt added for hardness and castability. This is the dominant standard for platinum bridal jewelry in most markets.

The Pt-prefix format follows Japanese and broader Asian marking convention, where platinum is graded as Pt850, Pt900, Pt950, and Pt999. Seeing PT950 often suggests manufacture in or for those markets, though the style is now used internationally. In the United States, FTC guidance allows an item of at least 950 parts per thousand platinum to be marked simply 'Platinum' or 'PLAT,' so PT950 and an unqualified PLAT stamp describe essentially the same metal. In the UK, platinum has been hallmarked since 1975, with 950 as the principal standard.

Platinum's appeal in rings is practical as well as prestigious. It is dense — noticeably heavier in the hand than gold — naturally white without rhodium plating, and hypoallergenic for most wearers. When scratched, platinum tends to displace rather than lose metal, so a well-worn band keeps most of its weight and can be repolished for decades.

On value: platinum trades on its own spot market, at times above and at times below gold. A PT950 ring's worth combines metal weight, brand, craftsmanship, and any stones, so metal price alone rarely tells the full story.

The PT950 stamp sits on the inside of the band, often near a maker's mark, a size mark, or a stone-weight notation on engagement rings. Variations include Pt950, PT 950, 950, PLAT, or 950 PLAT. On rings with slim or engraved bands the mark can be tiny and partially worn from resizing, so a loupe helps; a jeweler can confirm the metal with a quick test if the stamp is illegible.