I believe it is red coral. It has an ivory figure on the front that looks like a woman holding something. I can't tell if it is an umbrella, an urn, a vase, or something else.
The hallmark appears to read SRS10 , it is hard to read w/ my magnifying glass and even harder to get a good picture of.
If anyone can identify this ring and tell me about it I would appreciate it. I have spent a lot of time online and can't find another ring that looks like it. Any help would be appreciated and would help a lot.
The front:

A side picture:

The hallmark:

.