Every diamond in existence possesses an attribute called light performance, which decides how highly valued it can be after getting cut and polished. Light performance can be defined as the visual effect caused by light that enters and exits a stone, which can move straightly, bend, and get reflected based on the medium it flows through. Other gemstones are not as heavily affected by light performance as diamonds are, for the simple fact that they are nowhere near as dense.
The measurement and grading of light performance can be done through the use of advanced technologies, which help in figuring out the degree to which light gets reflected back to the observer. The “brilliance” measurement in the diamond industry, for example, stands for the intensity of bright light shining from a diamond, while “fire” stands for the components of the spectrum it emits distinctly.
Problems with Understanding Diamonds
Any non-professional would find choosing a diamond a very hard thing. The main cause of this is the inability to tell most stones apart, unless one is a duly educated professional or an experienced jeweler. This means the average buyer has to glean relevant information from a lab report, or the frequently less reliable advice from a salesperson.
Barring the use of a loupe, a grading report is the only way you can be sure of the quality of a specific stone. There are also diamond imaging systems which can display the stone in a virtual manner, but while these enhances the level of detail, they do not properly explain how a stone looks, or why it costs considerably more than another visually similar diamond. For that, you would need to compare stones based on light performance.
The Importance of Light Performance
For the newest generation of diamond buyers, a lab report, combined with the look of the stone, as well as the sincerest assurance from the sales rep, can still fall short of allaying the typical wariness with which they approach a diamond purchase. Here, light performance is often a good gauge to go by.
A diamond’s physical structure causes any light entering it to bend and then come back out. The observer senses a certain play of said light, which affects the “performance” of the stone. Its cut is instrumental to how it performs under different types of light. Too shallow a cut, and you would have light leaking out the bottom, making some areas go effectively dark. Meanwhile, a deep cut would get a lot of the light lost inside the structural depth of the stone.
Even the other physical features play an important role. A dully colored diamond, for example, would not be able to reflect light as effectively as a brighter one. Internal flaws too can get in the way of proper light performance, based on where these are located inside the stone, and how big they are.
A plethora of variables characterize the way the diamond is able to reflect light, which is why standardized measurement systems are in place in the diamond industry to gauge light performance in jewelry grade stones. Such systems use a range of parameters to define light performance, at the end of which a grade it assigned to the measured stone.
Light Performance Scale
Years of research into diamonds and the way they behave under light have yielded four ways in which a stone’s light interaction can be expressed quantitatively. These are Brilliance, Fire, Sparkle, and Light Symmetry. Each of these needs to be checked and then combined to arrive at an overall grade for light performance, which allows a retailer to sort and price stones based on their objective worth.
From a practical viewpoint, this is much easier than following technical grading. The customer gets to go through stones that are visually beautiful, as well as within budget; the 4 C’s grades can obfuscate this aspect, because none of those parameters deals with the visual performance of a stone. In contrast, a light performance grade gives a pretty clear and standardized objective measure of the diamond’s quality.
This works so well for so many people that light performance often gets called “the 5th C”. Many experts believe it is the better way to grade a diamond. When it comes to brass tacks, the shine and brilliance of a stone matter much more than what its actual properties are. It is important to note that most people hold on to their diamond-studded rings and pendants through life, which means basing a purchase on future resale value is not always the way to go. While it does offer a level of security, it may also be the reason you have to settle for a less attractive stone. If appearance matters above all else, light performance is what you should base your diamond jewelry choices on.