Rudolf Erdel Platinum and 18K Yellow Gold Montana Sapphire Engagement Ring. The center stone is a 5.0 mm Montana Sapphire weighing 0.61 carats.  It measures 4.52 mm at the top of the shank and tapers to 2.41 mm at the bottom of the shank. It is Finger size 7 and it can be sized. It is platinum with a yellow gold center.  It has a high polish and matte finish. There is a matching wedding band for this ring that is listed also. 

100-60-838