An unfaceted, highly polished, cut gemstone, in which the top of the gem forms a dome-shaped or curved, convex surface. The base may be flat, convex or concave. The girdle outline may be round, oval, square, triangular, polygonal, or any other fancy shape. Usually, a cabochon stone is one cut from a poor quality or a translucent to opaque mineral, or material, and those with a special optical effect, such as opal, moonstone, adularia, asteria etc. Stones with needle-like inclusions are cut with high cabochon, to obtain a star-like effect or eye-like effect.