Hallmark in antique ring

I received this ring from my great grandmother. It has this Mark on the inside but I have no idea what it is. A jeweler told me it's old but that's all he said. I've searched for years to try to figure it out. I just don't want to wear it if it's something I shouldn't.

 

wear it in her memory....

18 K

 

Thanks for the reply! I knew the 18k, I can't figure out what the sideways "s" symbol is though. I've worn it every day since I got it but I'm afraid I'll ruin it or wear it out and since its an heirloom I want to be safe.

 

Looks like it is from the 1940's,the maker's mark doesn't matter.

 

Could be a bit older, Edwardian.
Wear it and have the mount checked every second year or so. It looks ok now, but with daily wear those little claws can wear. That can easily be repaired.

 

Id guess 1940s too,it looks like my moms (before she melted it down and had it made into a different ring) and she got hers used in 1958. The jeweler told her it was 1940s.

 

My mother had it's sister, given to her in 1936.