11.8 carat star sapphire in a handmade platinum mounting. This is put together in super old-school methods. The whole thing is welded together in 1700 platinum- which is the most difficult way, but also the best way. Natural star sapphires almost all require custom settings to be made for them because they are all so individual. Being almost always really "bowly" on the back and super tall, they require tall and strong prongs. This star sapphire has really captured my heart because it has two parallel stars that flow all over the whole surface. It is a gorgeous blue-grey color. Yeah I kind of obsess over star sapphires.-you should see the google ads on the sides of my searches. The back of the pendant has a nicely domed sheet of platinum with some well-placed hallmarks.