Okay, let me walk you through how I figured out these platinum markings on jewelry. It wasn’t like I read a manual or anything, it was more just handling pieces over time and getting curious.

It started when I got my hands on a few rings that looked like white gold but felt way heavier. I remember thinking, “What’s the deal with this?” So, the first thing I did was grab a loupe, you know, one of those little magnifying glasses jewelers use. I started looking really closely, especially inside the bands.
At first, it was just tiny scratches and maybe some dirt. But then, on one piece, I spotted some super small letters stamped in. I had to angle it just right under the light. Saw a “P” and a “t”. Took me a second, but then it clicked – Pt. Okay, likely platinum. Then I saw another piece, this one clearly stamped “PLAT“. Simple enough, right? Those were the easy ones.
Getting into the Numbers
Then things got a bit more confusing. I started seeing numbers alongside the “Pt”. Like “Pt950” or sometimes just “950” next to the Pt. What did that mean? I initially guessed it was some kind of style code.
I asked around a bit, looked at more pieces, compared them. Turns out, those numbers are pretty important. They tell you how much pure platinum is actually in the metal mix. Most of the stuff I saw was:
- 950: This seemed the most common. Found out it means the metal is 95% pure platinum, with the other 5% being other metals mixed in, usually to make it harder because platinum itself is kinda soft.
- 900: Saw this one too, meaning 900 parts out of 1000, or 90% pure platinum.
- 850: Less common, but popped up occasionally. That’s 85% pure platinum.
So, basically, the higher the number, the more pure platinum you’ve got. The standard seems to be that Pt950 mark, that’s what you see a lot.

Other Little Details
Sometimes the marking looked a bit different. I remember seeing “PLATINUM” spelled out completely on an older piece. And occasionally, you might see other letters mixed in, indicating the specific alloy metals used, though that got a bit more complex than I usually bothered with.
The key thing I learned was just to look closely. These stamps can be really tiny, and sometimes they get worn down over years of wear. You need good light and maybe that loupe I mentioned. I found it helpful to just handle a lot of pieces. You start to get a feel for the weight and look of platinum, and you recognize the common markings faster.
So yeah, that’s my journey with figuring out platinum marks. No fancy course, just looking, comparing, and asking questions when I saw something new. You just gotta pay attention to those little stamps inside the jewelry.