I usually buy rings with finished cabs. However, i on occasion buy rings that exhibit some of the natural characteristics of turquoise nuggets. I have heard this type called by a dew names: “brain” cab, “nugget” cab, etc.
I typically don’t like domed cabs because I am always worried about hitting it on something. That said, I love this piece. Deep blue with deep brown/black matrix. Pyrite inclusions.
Given the size of the nugget, I would guess kingman. Old school kingman, maybe 70’s or so.
This is stamped “RT”.
Just wanted to share! Have a good day!