Sometimes, S may not be used, but the silver content must be .925, which means that the silver content in jewelry is
92.5%.
At present, the most common one on the market is 925 silver. Others such as 98 silver and 80 silver are relatively rare. (80 silver is more used as tableware than jewelry)
When buying, first check whether there are any marks. In addition, we should ask the seller to issue a formal invoice with a financial stamp. The ticket should be marked as "silver" jewelry.
After you come back, you can do a simple test: use the yolk of a hard-boiled egg, take a small piece and put it on an ornament (choose a less conspicuous place). After a while (1-2 minutes), see if there is any discoloration (it turned out to be silvery white and turned into dark and tan). If it changes color, it means it is real silver! This is a very sensitive chemical reaction.
Egg yolk contains sulfur. When sulfur meets silver (Ag), it will form brown silver sulfide (AgS).
If it doesn't change color, it means that the jewelry is not silver. You can negotiate or complain with the invoice.