What do you mean by “Cabochon Stone”?
In the world of jewelry, a cabochon is a stone that is cut with a flat or slightly domed base and a curved or domed top. Rose cut cabochons have triangular or square flats cut into the domed top. The term cabochon is often shortened to “cab”.
A cabochon may be cut in any shape, though rounds and oval are the most common.The term comes from the French word caboche, meaning knob or small dome. Technically, cabochons are not really “cut”. Rather, they are shaped and then polished. Before the art of faceting was developed in the early 14th century, all gemstones were produced as cabochons, some with intricate carvings as well.
Certain stones are almost always cut “en cabochon”, including opal, amber, turquoise, onyx, moonstone, and star sapphire. In many cases it is because the gem has special properties that are displayed only when it is cut as a cabochon. Gems that display optical phenomena such as asterism (like star sapphire), chatoyancy (the cat’s eye effect), iridescence (like opals), or adularescence (like moonstone) are more easily seen when cut as cabochons.
Gems that are opaque are cut as cabochons rather than faceted, since they will reflect no light. Also, lower grade material of gemstone types such as sapphire,ruby and garnet can be cut as cabs. If the gem material has very good color but is not sufficiently transparent or clean to be faceted, it can still be shaped and polished into very attractive cabochons.
It is also common to cut softer stones – like turquoise and amber – as cabs, since they can easily be scratched. Minute scratches show much less on a cabochon than on a faceted stone. Softer cabochons are also usually set in a bezel – a protective ring of metal that surrounds the stone. Harder cabochons can be set in either bezel mountings or prong mountings.