Decoding Jewelry Stamps: Understanding Platinum Markings (901 PLAT)

Question
Hi there

I have an engagement ring belonging to my late mother and would like to know what the stamps means on the ring.

It has the following marking

901 PLAT        16812

I would appreciate your help.

Answer
In my profile I state that I can't help with stamps and markings, but this one seems pretty straight forward.

It seems obvious it's platinum. Platinum is rated with a 3 digit number that essentially equates to its purity. 995 is usually about the highest you'll see in a piece of jewelry and indicates that the platinum is 99.5% pure. In this case, you're looking at 90.1% pure platinum. The rest is likely to be silver or copper but could be some other metal such as paladium, gold, or even zinc depending on what the jeweler decided to use.

The other number has no significance to me, so I would assume it is some sort of serial number, model number, or perhaps design or inventory number. It could have some cryptic meaning to the jeweler, but many jewelery stamps are unique to the individual jeweler or manufacturer and you'd have to ask him/her to know for sure.

I hope this helps. Be sure to leave a rating. Thanks.