Help in finding answers to my item

[Steven Grim]

Hello, I found this while metal detecting in Wisconsin, dark green stone or glass, heavy damage to filigree work.
Any help or identification on item such as purpose , age, material
Thanks, Steven

 

[AGBF]

I have no idea about the things I wanted to identify (the stone, the metal), but what struck me (and perhaps completely incorrectly) was that the woman's face looked like Queen Elizabeth II. My eyes are not at their best and my computer screen is not, either. Could that be she?

AGBF