Karat, how to tell on yellow gold?

[Layne]

I have an older ring from my mother than I belive is yellow gold. The only stamp that I see on the inside of the band is worn down- it might say R or K and 50. I''m not familiar with gold markings but this does not seem to indicate karat, does it? I do believe that this ring is gold as it has not tarnished as some older plated jewelry I also recieved around the same time. Also, the main stone is an oval garnet and it has a scratch on the surface, and does not appear to be very deep. Is there an easy way for a jeweler to polish it out?

thanks for any advice you might have!

 

[partgypsy]

The marking could be originally "750" and worn down, which is equivalent to 18K gold (seen sometimes in European pieces)

 

[Layne]

I went to my jeweler and it is 14k gold. I guess there was a really worn down marking in it that he found (in a matter of seconds). Also, he didn''t think it would be worth it to polish the garnet for the cost. I did leave it there to be sized but I will take a pic when I get it back!