More About Diamonds
Always remember that the most important part of buying a diamond is to choose one that appeals to you personally. While it is important to understand the technical aspects of diamonds, it's most important to fall in love with your diamond!
What Makes a Diamond Special?
Beauty - The beauty and inner fire of the diamond has made this precious gem prized for centuries. Each stone's complex characteristics cannot be duplicated, and no two diamonds can ever be the same. Each stone is endowed with a personality and character uniquely its own.
Durability - A diamond is the hardest substance known to man, making it resistant to deterioration. When cared for properly, diamond jewelry can be worn every day and passed on as an heirloom to the next generation.
Rarity - Natural diamonds take millions of years to form, so the supply of these gems remains limited.
Enduring Value - Gem-quality diamonds have consistently retained their value, with many increasing in value, after years of being worn and enjoyed.
A diamond's cut impacts four aspects of the stone's optical and physical properties:
Luster - The quality and amount of light that is reflected off just the surface of the diamond. Luster is directly related to the hardness of the stone and the quality of its polish.
Brilliance - The amount of white light that is returned to the eye from both internal and external surfaces. Brilliance is determined by the quality of the diamond's proportions and polish, and also the number and size of inclusions inside the gem.
Dispersion - The display of spectral or rainbow colors, seen coming from inside of a diamond. Often referred to as "fire", dispersion is directly related to how well the stone is proportioned.
Scintillation - A diamond will show "scintillation", or "sparkle" when movement is involved. The viewer, the light source, or the diamond itself must be in motion for scintillation to happen.
Fluorescence is the visible light some diamonds emit when they are exposed to invisible ultraviolet (UV) rays. On a GIA Diamond Grading Report, fluorescence refers to the strength, or intensity of the diamond’s reaction to long wave UV, which is an essential component of daylight. The light emitted lasts as long as the diamond is exposed to the ultraviolet source.
Is fluorescence common?
Yes. Of the diamonds submitted to GIA over the past decade, approximately 25% to 35% exhibit some degree of fluorescence. However, only 10% of those show strengths of fluorescence that may affect appearance (i.e. strengths noted on laboratory reports as medium, strong, or very strong). In more than 95% of the diamonds that exhibit fluorescence, the color seen is blue. In rare instances, the reaction is yellow, white or another color.
What impact does fluorescence have on the appearance of a diamond?
GIA studies show that, for the overwhelming majority of diamonds, the strength of fluorescence has no widely noticeable effect on appearance. In many instances, observers prefer the appearance of diamonds that have medium to strong fluorescence. In rare cases, some diamonds with extremely strong fluorescence may appear hazy, or oily; fewer than 0.2% of the fluorescent diamonds submitted to GIA exhibit this effect.
Does fluorescence compromise the structural integrity of the diamond?
No. A diamond that fluoresces has the same integrity as one with no reaction to UV. Submicroscopic substitutions and/or shifts in the diamond structure can cause fluorescence as well as prevent it. Nothing in either instance inherently weakens or is bad for the diamond.
Technology advances in recent years have made it possible for natural diamonds to be enhanced, which increases their beauty and affordability. Diamonds can now also be grown in a laboratory environment. These synthetic diamonds have the same chemical, physical and optical properties as natural diamonds, but lack a natural diamond's uniqueness, rarity and value. It is very important to discuss with your professional jeweler if the diamond you are purchasing has been enhanced in any way. Most enhancement treatments require special care, of which you need to be aware.
While many of these are not common in the market, GIA tests every diamond it grades for their presence. Coating enhances a diamond’s color by masking an undesirable body color with an ultra-thin layer of chemicals of plastics. Another form of coating involves applying a thin film of synthetic diamond to the surface of a diamond simulant, giving it certain characteristics of a real diamond. HPHT stands for high-pressure, high-temperature. The process is an effective tool for changing the color of certain diamonds, making them colorless, pink, blue, green, yellowish green, or yellow. Outside of well-equipped grading laboratory, this form of treatment is virtually undetectable.
There are two main techniques for improving a diamond’s apparent clarity: laser drilling and fracture filling. Laser drilling is commonly used to remove small dark inclusions. The laser bores a small hole into the diamond’s interior and burns away the inclusion, or creates a channel through which a bleaching agent can be introduced to improve the inclusion's appearance. Fracture filling hides white fractures in a diamond called “feathers.” A glass-like substance is injected into the fracture to make it less visible and to improve the stone’s apparent clarity. Because the filling may be damaged or removed during routine cleaning and repair, the technique is controversial. Good fracture filling is very subtle, and so examination by a skilled diamond grader is necessary to detect its presence in a stone.
Synthetic Diamonds are stones that are grown in a laboratory, under controlled conditions. These stones have all of the same properties of a natural diamond, and it is very difficult to separate them from natural diamonds without special training and equipment. While not currently readily available in larger sizes, in the future, these created stones will be more prevalent in the marketplace.