bling aijewelry stamps · platinum
solid metal850 stamp on platinum: what it means.
850 means 85% pure platinum. it's usually marked Pt850 and turns up mainly on chains, settings and some older or asian-made pieces.
- metal
- 850 platinum
- 85% platinum
- also stamped as
- 850 · Pt850
- solid or plated
- solid all the way through
what it's worth today
live spot price · updated Sep 24, 2026, 12:47 AM UTC
melt value of the metal only, from the live spot price. buyers pay less than melt; stones, craftsmanship and maker add value.
the mark
what 850 means.
850 is 850 parts platinum per 1,000. the extra alloy makes it harder, which suits chains, clasps and settings that need to hold their shape.
it's less common than Pt950 or Pt900, and it's the lowest platinum standard you'll usually find stamped on jewelry.
before you trust it
how to check a 850 stamp.
- look for Pt before or after 850. without it, the number alone isn't enough to call the piece platinum.
- feel the weight. platinum is very dense, so even a small chain feels heavy for its size.
- for certainty, ask a jeweler or gold buyer for an XRF scan. it reads the metal's composition in seconds without scratching the piece, unlike an acid test.
questions
the 850 stamp, answered.
other stamps
every mark is searchable in the hallmark decoder. selling vintage or estate pieces? see photography for vintage and estate sellers.
selling what you found?
photograph it like it's worth something.
bling ai turns a phone photo of a piece into a listing shot that looks like a campaign, so good jewelry sells for what it is.
