One of my favourite rings

Already a lot of years ago I inharited this beautyfull old ring with rose cut diamonds and closed back. The diamonds are set in silver I suppose, because this was done often in those days and the back site of the ring is in yellow (I think at least 14K) gold. The diamonds are quite huge especialy the two in the middle. In earlier times I let enlarge the ring and then I did'nt know yet much of the value of this ring. I'am afraid that perhaps with this action they also removed hallmarks. But I'm not sure if there has been at all.
Please can you give me an idea of the time period of this ring? Thanks in advance !