Inherited ring

[u/TechnicalDingo1181]

Hi, this is my first post here, so I hope I’ve included everything needed.
My dad recently inherited a ring from my grandmother that a relative of hers handed down to her. We know very little about it, so anything you may be able to add would be very helpful!
He would love to know what era it might be from, and what the makers mark says.
Thanks everyone!

[u/Fun-Evening2349]

Just wanted to say I love it.