Dating by 925 vs Sterling mark?

[gameolife]

I have had a 'rule of thumb' for dating jewelry that goes..if the mark is '925' it is 1950-today. That all older pieces used the word 'Sterling' and never the numbers. Is this correct?
I currently have a Camphor glass necklace and bracelet marked '925', so am assuming it's a reproduction.

Thank you!
Celia