Editing Diamond cutting (section)

====Maximizing value====
[[Image:Diamond cutter's shop in 18th century.jpg|thumb|Man-powered diamond cutting mill in 18th century]]
The process of maximizing the value of finished diamonds, from a rough diamond into a polished gemstone, is both an art and a science. The choice of cut is influenced by many factors. Market factors include the exponential increase in value of diamonds as weight increases, referred to as ''weight retention'', and the popularity of certain shapes amongst consumers. Physical factors include the original shape of the rough stone, and location of the inclusions and flaws to be eliminated.

=====Weight retention=====
The weight retention analysis studies the diamond rough to find the best combination of finished stones as it relates to ''per carat'' value. For instance, a 2.20-carat (440&nbsp;mg) octahedron may produce (i) either two half-carat (100&nbsp;mg) diamonds whose combined value may be higher than that of (ii) a 0.80-carat (160&nbsp;mg) diamond plus a 0.30-carat (60&nbsp;mg) diamond that could be cut from the same rough diamond.

The round brilliant cut and square brilliant cuts are preferred when the crystal is an octahedron, as often two stones may be cut from one such crystal. Oddly shaped crystals, such as [[macle]]s are more likely to be cut in a ''fancy cut''—that is, a cut other than the round brilliant—which the particular crystal shape lends itself to.

Even with modern techniques, the cutting and polishing of a diamond crystal always results in a dramatic loss of weight, about 50%.<ref name=x50>{{cite book |url=https://books.google.com/books?id=jPT6JADCqgwC&pg=PA280 |page=280 |title=Handbook of carbon, graphite, diamond, and fullerenes: properties, processing, and applications |author=Pierson, Hugh O. |publisher=William Andrew |year=1993|isbn=0-8155-1339-9}}</ref> Sometimes the cutters compromise and accept lesser proportions and symmetry in order to avoid inclusions or to preserve the weight. Since the per-carat price of a diamond shifts around key milestones (such as 1.00 carat), many one-carat (200&nbsp;mg) diamonds are the result of compromising ''cut quality'' for ''carat weight''.

=====Color retention=====
[[Image:DiamanteEZ.jpg|thumb|right|The 253-carat [[Oppenheimer Diamond]]—an uncut diamond does not show its prized optical properties]]
In colored diamonds, cutting can influence the color grade of the diamond, thereby raising its value. Certain cut shapes are used to intensify the color of the diamond. The radiant cut is an example of this type of cut.

Natural green color diamonds most often have merely a surface coloration caused by natural irradiation, which does not extend through the stone. For this reason green diamonds are cut with significant portions of the original rough diamond's surface (''naturals'') left on the finished gem. It is these ''naturals'' that provide the color to the diamond.