What techniques were used to make this ring?

I’m hoping to learn more about a ring my mom gave me. She told me it has been in our family for many generations - going back to at least the late 1800s.

It has a really interesting construction that I haven’t seen before. The design looks like a cage, with thin (open work?) wires/bars all around it. My mom has taken it to jewelers in the past but they’ve only told her they wouldn’t touch it, without giving much detail.

I’m not looking to sell it - just curious about the techniques that might have been used to make it.