A cultured pearl differs from an imitation pearl much as a synthetic differs from a paste stone. A cultured pearl is naturally developed by an oyster which has been artificially inseminated. Man starts the process, the oyster carries it through. About 1920 an ingenious Japanese inserted a tiny bead of mother-of-pearl into an oyster; the result was the first cultured pearl. Since the oyster is first captured, then inoculated, then released under controlled conditions, the processes of production can be kept less haphazard, the time speeded and the quantity increased. As with synthetic gems, however, there are tiny indications, in structure, in lustrousness, by which the cultured may be distinguished from the native pearl. _Cutting the Stones_ I have mentioned that the cutting may help to bring out the brilliance of a stone. There are two main types of cutting: the cabochon, used from earliest times; and the faceting, used increasingly over the past four centuries. Each is still valued for particular stones and purposes. _Cabochon_ A stone cabochon cut is cut in a smooth upward (convex) curve, like the arc of a circle or an ellipse. Most frequent is the medium cut, a smooth oval with the under surface flat. The steep cut produces a dome-like effect, as of a small haystack or high mound. In the hollow cut, the upper surface is convex and the lower surface is concave, the effect being that of a small bar curving upward. The fourth commonly used cabochon cut is the double cut, the upper surface curving up and the lower surface curving down, like a tiny elongated football. Which of these cuts is used depends partly upon the jewel for which the stone is intended, but mainly upon the original shape and coloring of the stone. _Facets_ Transparent and translucent stones which seem to have radiance are usually made more beautiful by faceting. A facet is a small, smooth face or plane surface; a number of these are cut upon a gem. In most facet-cut gems five regions can be distinguished. The table—the top of the stone—is usually flat, though it may be slightly domed; it is usually the largest of the facets, though the size may vary according to the stone and the type of cut. The bezel is the slope from the top, consisting of slanted, smooth faces that may proceed in various planes or by ninety-degree “steps” down to the girdle. The girdle is the widest part, the “equator,” of the cut stone; it is here that the setting is usually attached. The pavilion is the part that slants down from the girdle to the culet, which is the bottom point of the stone. Sometimes the stone is slightly truncate; that is, it is cut to a small flat surface, instead of a point, at the culet. More generally, the part of the stone above the girdle is the crown; the part below the base. _Types of Faceting_ There are many patterns of faceting. Six are fairly common.