The color and transparency suggest aquamarine, or blue beryl. On the hand, it gives a pure, calm blue; visually, it can be confused with blue topaz.
The crown with fine "teeth" and the thick, ribbed band are a signature of the region. The silver has a patina, with oxidation in the crevices – this is exactly how an old piece is supposed to look.
This shade works best with grays and graphite. It doesn't need company – one ring, and the entire look is the focal point.
Aquamarine / blue beryl – regardless of the name, it's a solid, natural stone in a raw, Pakistani setting.