This Art Deco signet style ring is in incredible condition. I purchased the mounting with nothing mounted in it, it was probably removed at some point. The Pietersite was custom cut to fit this ring and it came out beautiful.  Half the stone has silky chatoyancy giving it the appearance of labradorite and the other half looks like tigers eye. It is such an interesting and masculine stone, perfect for this ring. 
Gemstone: Pietersite
Shape: Cushion
Measurements: 15 x 13 mm
Dimensions: 20.9 - 3.1 mm wide / 3.9 mm high off finger
Size: 9
Metal: 10k Yellow Gold 
Markings: OB.10K
Circa: late 1920's
Weight: 5.6 grams
Condition Rating: 8 (had stone cut for this mounting)