Antique Ring What kind is it?

Hello,

I have this ring that has been passed down from about 4 generations. I have no clue about its history only that it was a engagement ring from my family. It has been held in a safe for many years. It was passed down to me when my mom passed 4 years ago. From what I am trying to research it looks like a Edwardian ring I think maybe the markings are filigree. Inside it says platinum but is worn but you can still make out what it says. It has  leaf designs around the diamond. If anyone could give me a idea about anything about this ring it would be so much appriciated. I am enclosing pictures that I hope help.

Thank you,

Cat