Cabochons are a type of gemstone that have a flat bottom and a domed top. They are used, sometimes, to get a gemstone out of material that may not otherwise be cutable.
However, this stunning cab could have been cut into a faceted stone. Instead, a goregous tourmaline cabochon was cut. The stone measures 11 x 9 mm and weighs 4.8 cts. It was mined at Mt. Mica. The accents stones are bright blue sapphires (which were not mined in Maine).