Gemstone

A cabochon or cabachon, from the Middle French caboche (head), is a gemstone which has been shaped and polished as opposed to faceted. The resulting form is usually a convex top with a flat bottom. Cutting en cabochon is usually applied to opaque gems, while facetting is usually applied to transparent stones. (Wikipedia) With a choice of 6 gemstones; amber, lapis lazuli, malachite, amethyst, rainbow moonstone and turquoise..