This large-sized 10 ring is of recent vintage and has a gorgeous chrome diopside, sometimes called the "Siberian emerald". The stones in the rough are often found above ground by stream beds. This ring is very sparkly but the diamonds are really tiny, though fully cut, and are slightly included. The face of the ring is 1/2 inch and it spans 7/8 inch across the finger. I don't think chrome diopside are precious stones, but they aren't the green glass "stones" from Mount St. Helen either! Nature makes them green; heat my enhance the color, I really don't know. I bought this way back for myself, and I all I considered were appeal and price tag!