You've stumbled across a large, 14k solid gold French cushion cut smoky quartz ring with an interesting setting featuring  star and infinity themes.  The big center stone measures 12mm across and is secured by four heavy teardrop prongs. The cartouche in the setting is decorated as well as the star motif in the shank with pleasing effect.
The ring is sized to fit a size 6 finger, but can be sized up or down for a fee.