How to Grade Fancy Cut Diamonds
Fancy cut diamonds can have any finished shape, except round. These stones have their own grading criteria, in particular regarding proportion and symmetry.
10 Minute Read
Gemologists can generally use the same diamond color and clarity grading standards for both rounds and fancies. However, in terms of cut (proportion and finish), fancy cut diamonds differ significantly from standard rounds.
Although the term “fancy” is also used to describe colored diamonds, fancy cut diamonds can be either colorless or fancy colored.
What are the Differences Between Rounds and Fancy Cut Diamonds?
Lapidaries cut fancy shapes to obtain the maximum yield from oddly shaped diamond rough. Although they occur less frequently than octahedrons, many broken pieces of rough are found. In addition, if lapidaries need to cut inclusions of out regular octahedrons, odd shapes may result. Rather than greatly reducing the weight of a finished diamond just to accommodate a round brilliant design, most lapidaries will cut a fancy shape instead.
Faceting Rounds vs Faceting Fancies
In a round diamond, all the facets in a tier are cut to the same angle and depth. Thus, rounds are easier to cut compared to fancy shapes. Whereas automated machines usually cut rounds, fancies must be cut by hand. Since this takes a lot of time, you’ll usually see fancy cut diamonds in larger sizes than rounds.
Donald Clark, CSM IMG
The late Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters “CSM” after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff’s ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book “Modern Faceting, the Easy Way.”
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