Hi Marion thanks for writing in. The letters - EHR on grandmother's antique gold ring will most likely be the maker's mark, the Q will be the date letter, and the upside down cross I will not be able to comment on until I see a photo.
Please up load a photo of the marks in a follow-up submission. Please use "Gold Ring with Hallmarks" in the heading so that I can assign the photo to the original question here. It just saves a lot of time.
