The most commons marks are
'850 Plat' or '850 Pt'
OR
'950 Plat' or '950 Pt'
you get the marking app from the poketch company.
Platinum
The ring should be marked "pt" or "plat" and have the amount of platinum in the ring, such as "850 pt." THE MARKING IS "PLAT." WITHOUT QUOTES
Go and talk to the owner of poketch in poketch company's building he will install the marking map app in your poketch
Zapdos, moltres, and articuno are only roaming around in Platinum.
You have to go to Jublife City, into the Poketech building. Talk to the man in front of the counter, and he will give you the marking map.
One of the easiest ways to tell the difference between stainless steel and platinum jewelry is by the markings. Platinum will have a marking such as "Plat", "PT", or will have "Platinum" etched in the piece.
You can find articuno in the poketch marking app when he's all around
App is not an item, it is those things that you put into youir poketch, such as the marking map.
HMS is a company that specializes in 18k, 14k, 10k and platinum jewelry
of course you can if you go to the poke etch creator he gives you various due to how many badges you have
go to verity lake talk to mesprit and it will disappear then professor rowan will come up and give it to you.