Editing Diamond cut (section)

{{For|the Bonnie Tyler album|Diamond Cut (Bonnie Tyler album)}}
{{Short description|Type of cut used when shaping a diamond}}
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[[File:Diamond cut history.svg|upright=1.3|thumb|Diagram of old diamond cuts showing their evolution from the most primitive (point cut) to the most advanced pre-[[Tolkowsky]] cut (old European). The rose cut is omitted, but it could be considered intermediate between the old single and Mazarin cuts.]]
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A '''diamond cut''' is a style or design guide used when shaping a [[diamond]] for polishing such as the [[Brilliant (diamond cut)|brilliant cut]]. Cut refers to shape ([[Pear cut|pear]], oval), and also the symmetry, proportioning and polish of a diamond. The cut of a diamond greatly affects a diamond's brilliance—a poorly-cut diamond is less luminous.

In order to best use a diamond [[gemstone]]'s [[material properties of diamond|material properties]], a number of different diamond cuts have been developed. A diamond cut constitutes a more or less symmetrical arrangement of [[facet]]s, which together modify the shape and appearance of a diamond [[crystal]]. [[Diamond cutting|Diamond cutters]] must consider several factors, such as the shape and size of the crystal, when choosing a cut. The practical history of diamond cuts can be traced back to the [[Middle Ages]], while their theoretical basis was not developed until the turn of the 20th century. The earliest diamond cutting techniques were simply to polish the natural shape of rough diamonds, often octahedral crystals it wasn't until the 14th century that faceting, the process of cutting and polishing a gemstone to create multiple flat surfaces or facets, was first developed in Europe.<ref>{{Cite web |title=Faceting {{!}} gemology {{!}} Britannica |url=https://www.britannica.com/art/faceting |access-date=2025-04-21 |website=www.britannica.com |language=en}}</ref> Design, creation and innovation continue to the present day: new technology—notably [[laser]] cutting and [[computer-aided design]]—has enabled the development of cuts whose complexity, optical performance, and waste reduction were hitherto unthinkable.

The most popular of diamond cuts is the modern round brilliant, whose 57 facets arrangements and proportions have been perfected by both [[mathematics|mathematical]] and [[empiricism|empirical]] analysis. Also popular are the [[#Fancy cuts|fancy cuts]], which come in a variety of shapes, many of which were derived from the round brilliant. A diamond's cut is evaluated by trained graders, with higher grades given to stones whose symmetry and proportions most closely match the particular "ideal" used as a benchmark. The strictest standards are applied to the round brilliant; although its facet count is invariable, its proportions are not. Different countries base their cut grading on different ideals: one may speak of the American Standard or the Scandinavian Standard (Scan. D.N.), to give but two examples.