I am forever mesmerised by star sapphires. I have one very similar to this in my own collection which is one of my most favourite pieces. 
A gorgeous purplish-pink natural star sapphire cabochon, which we have added to a vintage 18ct gold band with a chubby handmade bezel setting. You will find yourself staring at this a lot.
Full UK hallmark for 18ct gold, London 1976. 
Weight approx 4.40g
Sapphire 1.32ct 
Width of band approx 3.2mm
Finger size N 1/2 (approx US size 6.75) resizing is possible