I would say 99% sure smokey quartz. They were soooo typical in the 70's and the ring is typically 70s in style with those bark finished shoulders. For very many years I was in the retail trade and we bought and sold lots of jewellery. We saw lots of rings in this claw set style style and others...most claw set with smokey quartz.. Topaz tends to be rather more expensive than quartz, and it's less likely to see topaz set in 9ct, particularly in a relativity modern ring.