All diamonds look nice under bright lights, but most become noticeably average in normal conditions. Those which continue to sparkle and dance have good cut quality. At Fortrez Diamonds we separate cut quality into two areas; Cut Performance, which revolves around light return, and Cut Precision which can take top performing diamonds to an even higher level.
Micro Cut Precision first became possible in the late 1980s in rounds and is only now surfacing in fancy shapes. This is a measure of how well all of a diamond’s facets align with each other in 3D. It takes improved tools, more time and higher skill sets to accomplish top precision. More importantly it expends more carat weight. When present in top-performing diamonds, cut precision can boost contrast, dispersion, scintillation and overall performance in low-light conditions.
Cut Precision is seen in reflective Optical Symmetry viewers, also known as Hearts & Arrows Viewers. These scopes use a single colour and no backlighting to show physical cut alignment. Where other viewers focus only on the crown view, the optical symmetry viewer shows both crown (top) and pavilion (bottom) views.
Note: These are not performance reflectors. They reveal nothing about light return, which is a prerequisite for cut precision to have benefits. Read about the AGS ASET® and Ideal-Scope® in our Performance Tutorial.
The diamond is set face-down to see pavilion cut precision. It is turned over, face-up, to see crown cut precision. When the viewer is placed over the diamond light from above is coded white and light from the sides is coded red (other colours may be used).
When the diamond is cut so exactly that its facet reflections overlap with each other it produces uniform, kaleidoscopic patterns in the viewer. Only a tiny fraction of the world’s diamonds will show crisp, uniform patterns.
The Round Brilliant is the only shape with a global nickname for cut precision (“Hearts & Arrows”). The reason for this is obvious when looking through an optical symmetry viewer.
Fancy cuts are not held to the same standards as Round Brilliants. The crisp uniformity of patterns seen in precisely cut rounds is not possible with more complex facet arrangements. As a result shapes other than round are practically never discussed in terms of cut precision. However, as the benefits of cut precision are studied by research labs and made known to consumers we are confident cut-focused manufacturers will begin to pay attention to their development.
Depending on configuration, a princess cut will have between 24-48 facets on its pavilion and 17-29 cut on the crown. This makes for a wide variety of looks even when the patterns are readable. The princess cut below has a 24 facet pavilion (known as “2-chevron”).
While the colours do not indicate levels of light return (AGS ASET® and Ideal-Scope® can be used for this) they show how well a diamond’s facets align with each other in 3D. Where other viewers focus only on the crown view, the optical symmetry viewer shows both crown (top) and pavilion (bottom) views.
Round Brilliant Examples in Optical Symmetry Viewer
Princess Examples in Optical Symmetry Viewer
Cut Precision fine-tunes diamonds which already enjoy top performance. The better-defined contrast pattern creates sharper on-off scintillation and more primary colours in dispersion (less pastels and earth tones). Precision cutting maximizes the return of all available light, even in softer lighting conditions. This is a logical result of all of the facets, the tiny mirrors inside the diamond, brought into precise alignment with each other. Face up colour is also improved when light gets in and out of a diamond with more intensity. This can be noted in many diamonds with above-average performance. High performance coupled with top cut precision enhances the effect even more.
Because few diamonds remotely approach this level of precision. All diamonds look nice under bright lights and these viewers reveal the lack of precision present in the vast majority of the world’s diamonds.
A high level of micro-precision takes modern tools and more time to achieve. It also requires polishing away more carat weight. Assembly-line factories with dated equipment would have to sacrifice more time and produce smaller diamonds to do this, costing millions in time and carat weight. Remember that most consumers are barely aware of how to judge cut quality. As of 2009 only a single digit percentage of the world’s diamonds are even cut for top performance. Far fewer have both top performance and top precision; easily fewer than 1% of all rounds and perhaps 0.01% of princess cuts.
Cut Performance should be a prerequisite for Cut Precision. Understanding that, diamonds which enjoy high performance and precision are dizzying, dazzling and rare treasures to behold. In fact, because of factory cost-effectiveness and lack of public awareness the performance & precision standards that we insist on make every one of our diamonds rarer than a D Flawless in terms of cut quality.
The bottom line? CUT is the most important factor to diamond beauty. Nature did her job by giving man an abundance of beautiful rough. At Fortrez Diamonds we think mother nature’s rough deserves nothing less than FLAWLESS cutting: The highest possible light performance and the most precise craftsmanship man can achieve.