Editing Diamond cutting (section)

==Diamond cutting process==
The basic diamond cutting process includes these steps; ''planning'', ''cleaving'' or ''sawing'', ''bruting'', ''polishing'', and ''final inspection''.<ref name="GIACutting">''Diamonds and Diamond Grading: The Evolution of Diamond Cutting'' [[Gemological Institute of America]], Carlsbad, California, 2002</ref> A simplified [[brilliant (diamond cut)|round brilliant cut]] process includes the following stages:
* Planning – Modern day planning of a diamond is done using computer software. 
* Marking – Outlining the best possible shape and cut of the diamond.
* Sawing the rough stone – depending on the shape of rough diamond as not all diamonds are sawn.
* Table
* Bruting the girdle.
* Blocking 8 main pavilion facets – these facets are divided into 4 corners and 4 pavilions as the corners and pavilions run in different directions due to the atomic structure of the diamond.
* Crown – the crown consist of 8 main facets and are divided into 4 corners and 4 Bezels.
* Final bruting – ensuring the diamonds girdle is perfectly round and smooth. 
* Polishing all 16 main facets.
* Brillianteering – Adding and polishing 8 stars and 16 pavilion and 16 crown halves.
* Quality control – checking for symmetry, polish and cut (angles) after the diamond is completed.

This is just one, although a fairly common way of creating a round brilliant cut. The actual process also includes many more stages depending on the size and quality of the rough stone. For example, bigger stones are first scanned to get the three-dimensional shape, which is then used to find the optimal usage. The scanning may be repeated after each stage and bruting may be done in several steps, each bringing the girdle closer to the final shape.

It is possible only because the [[mohs scale of mineral hardness|hardness]] of [[diamond]] varies widely according to the direction in which one is trying to cut or grind.

===Planning===
Diamond manufacturers analyze diamond rough from an economic perspective, with two objectives steering decisions made about how a faceted diamond will be cut. The first objective is that of maximum [[return on investment]] for the piece of diamond rough. The second is how quickly the finished diamond can be sold. Scanning devices are used to get a 3-dimensional computer model of the rough stone. Also, inclusions are photographed and placed on the 3D model, which is then used to find an optimal way to cut the stone.

====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.

====Turnaround minimization====
The other consideration of diamond planning is how quickly a diamond will sell. This consideration is often unique to the type of manufacturer. While a certain cutting plan may yield a better value, a different plan may yield diamonds that will sell sooner, providing an earlier return on the investment.

===Cleaving or sawing===
Cleaving is the separation of a piece of diamond rough into separate pieces, to be finished as separate gems. During the planning stage, diamond manufacturers identify [[Cleavage (crystal)|cleavage]] planes, and use those planes to decide how to split the diamond. Diamond manufacturers make a groove in the diamond with a laser or saw or another diamond, and then split the diamond by placing a steel blade in the groove and giving a gentle tap.<ref>{{cite web |author=Antique Jewelry University |title=Diamond Cleavage |url=https://www.youtube.com/watch?v=OhFRhfOedXA |website=YouTube}}</ref> Cleavage can be along any of the four planes parallel to the faces of an [[octahedral]] diamond (i.e. perpendicular to body diagonals of the unit cell).<ref>{{cite web |title=Definition of diamond cleavage |url=https://www.mindat.org/glossary/diamond_cleavage |website=Mindat.org}}</ref>

Sawing is the use of a diamond saw or laser to cut the diamond rough into separate pieces. Unlike cleaving, this step does not involve cleavage planes. This step gives diamonds their initial shape.

===Bruting===
Bruting is the art of cutting a diamond to make the girdle round. In the modern era diamonds are rounded using either a laser, a diamond disk impregnated with diamonds, or spinning two diamonds so they cut against each other. Industrial diamonds can also be used for bruting a diamond round. Modern computer software measures the roundness of each diamond and ''ideal cut'' diamonds have to round within a tenth of a millimeter to qualify as an excellent cut diamond.

===Diamond polishing===
[[File:Diamond Polisher.jpg|thumb|right|Diamond polisher in Amsterdam. Polishing is carried out by forcing a diamond against a spinning disk with abrasive.]]
Diamond polishing is the final polishing of the diamond. In a diamond factory, one would find a diamond ''crossworker'' who first places the main facets on a diamond (blocking the diamond). This is done to ensure maximum weight, clarity and best angles for the specific shape of diamond. After initial crossworking is complete, the diamond is finalized by smoothing the main facets by the crossworker, which is known as polishing the diamond. After the main facets have been polished by the crossworker, the final facets are polished onto the diamond by a ''brillianteer''. The facets added are the stars, top and bottom halves are also known as upper and lower girdle facets.

===Final inspection===
The final stage involves thoroughly cleaning the diamond in acids, and examining the diamond to see whether it meets the quality standards of the manufacturer.