Need help with ring markings

[leviathanrick]

Found a 1954 class ring that is silver in appearance and weight feels heavy like gold. Markings inside say 500K Sterling. Is anyone familiar with these markings?

 

[tamrock]

Not sure, but .500 - (50%) alloy gold would be the same as 12 karat gold.

 

[Sentrom]

Can we see a good photo of the markings? Is it stamped, part of the casting detail or engraved?

Palladium can be marked 500 the k could be the jewelers mark. Palladium Sterling is a sterling silver alloy. Palladium Sterling can be hallmarked as Sterling.