The Half Moon shape is straight on one side and curved on the other, creating a crescent shape.The straight edge lends itself well to setting against a center stone, particularly one with a straight edge.
PHYSICAL CHARACTERISTICS AND CUTTING ISSUES
In the 1920s and 1930s, Half Moons were step cut, as were triangular diamonds; more contemporary Half Moon cuts are faceted a little differently, using brillianteering similar to oval cuts. This makes for a more lively, proportionately cut stone with a culet. Years ago, Half Moons were cut from broken rounds with gashes on the side. The problem, however, was that you needed two broken stones of the same color for matching purposes. These days, Half Moons generally are cut in large quantities from octahedron and sometimes marquise rough. Pairs are not directly matched up with the rough from which they were cut, but rather many Half Moons in different colors, sizes and qualities – generally from I to SI2 for market purposes are cut, then matched for inventory. There is a large weight loss from Half Moon shapes in order to achieve the kind of brilliance the marketplace is demanding today, but exact percentages are not divulged.
MARKETS AND MARKETING
There is a big demand among designer/manufacturers for Half Moons, especially wider ones that are shaped like a half pie, or long, narrow ones that more closely resemble the crescent moon. Not only are Half Moons paired with diamond center stones but also with colored stone centers. Ninety-five percent of the market for Half Moons is for pairs, with typical sizes in the 30- to 40-points or .50carat to 1.5-carat total weight range. Half Moon pairs are most typically ordered by length first and then width to correspond with the designers’ center stones, although they sometimes are ordered by carat weight. With a round center, for example, Half Moons could be ordered in 5-by-4 millimeter sizes; with an oval center, in 7 -by-4 millimeters. Since they are sold as pairs, they must match each other as well as the color and quality of the center stone. A large color inventory of Half Moons from D downward is needed to meet the industry demand. There also is a small, secondary market for matched fancy-color Half Moons, which remains small because of matching difficulties with the pairs as well as with the center stone. In some cases, Half Moons are replacing trillions or Trielles as side stones of choice because they can be mounted lower than trillions and don’t take up as much side space, since they are significantly narrower than triangles.
PRICING AND SUPPLY
There is no particular shortage of the rough needed for Half Moons. When rough is in short supply in general, Half Moon cutters and dealers are likewise affected. Half Moons are priced according to weight, color and quality. A half-carat total weight pair in F color, VS2 quality would typically sell for $1,800 a carat, or $900 for the pair.
WHAT BUYERS SHOULD LOOK FOR
The number-one consideration is how well the stones match each other and the center with which they will be mounted. Length and width of Half Moons is a matter of personal taste, but generally, look for a ratio of 2 to 1 or 2 to 1.75 if more width is desired. Look for lively stones that will enhance the beauty of the center stone.