A gemstone is cut en cabochon when it has been shaped with a highly polished rounded or slightly domed convext top with no faceting and a flat or slightly domed base. Some cabochons may even have undulating surfaces. A gemstone with a flat bottom and a faceted domed top are often reffered to as rose-cut gems. A gemstone with a faceted pavilion, but featuring the smooth domed top of a cabochon are known as buff-top gemstones.
Gemstone cabochons may be cut into any shape, though oval is the most frequent. The term, "cabochon" comes from the French "caboche", meaning small dome. Many of the 130+ gem types are almost always cut "en cabochon", including opal, jade, turquoise, onyx, moonstone, and star sapphire. Cabochon is often shortened to "cab" by gem enthusiasts.
Gemstone cabochons are available in pretty much every color of the rainbow and may be star gems, cat's eye gems, transparent, translucent or opaque. Cabochons make excellent necklace pendants, gemstones rings, bracelets, earrings and more.