“China 925” and a symbol are on the inside of a gold ring (I can’t make out) . Is it real gold? 
The symbol for Sterling Silver is 925 which stands for 92 1/2% فضي. I have seen many of these and most of the time it is silver. Don’t be fooled by gold plating on silver, a common product called Vermil. Use a magnet, if it picks up with a magnet, it is fake. If it doesn’t it’s probably silver and should be priced as silver. The gold plating has little to no value.
I found a silver ring on the floor, on the back of it it says 925 CN FZN . It has a square piece on the front with shiny small diamonds in it . How much is it worth?
ربما ? Nothing for resale, unless somebody likes it.
Diamonds are RARELY set in silver, unless they are very low grade. Especially mass produced rings from China. It’s a silver (925), ring made. In China ( CN), and the FZN is most likely the manufacturer. If you like it, ارتدها, or give it to someone else that would, but it isn’t worth the effort to sell it. Sorry!
Who makes jewelry with Israel 925 stamped on the inside?
925” is the world-wide quality stamp for all sterling silver objects. It means that on a count of 1000 by weight), 925 parts are silver (one of the basic elements on the chart of elements), بينما تبقى 75 parts can be anything at all! Traditionally (although not necessarily), sterling silver has 7.5% copper (another basic element on the chart of elements). Thus, sterling silver is any silver alloy (an ‘alloy’ being a mixed metal) which is 92.5% فضي.
In the United Kingdom, individuals (metalsmiths) cannot stamp their items with quality marks—they must be assayed and stamped by the authorities. But throughout most of the world, like in the US and in Israel, anyone can stamp their own merchandise. So if you find jewelry in Israel which is stamped 925, it is supposed to be silver, but may not be if it was dishonestly stamped. Jewelry purchased in reputable jewelry stores is very likely to be silver if stamped 925. The store would get into a lot of trouble if it were discovered they were selling non-silver jewelry as silver. Jewelry purchased in markets ar bazaars may not be silver even if they are so stamped. All of this is true for gold as well. I have seen ‘gold’ items purchased by Philippina caregivers in the Old City (Jerusalem) stamped 18K which do not appear to me to be gold at all…..