Determining Diamond Quality: The 4 C’s

Diamond, grading diamonds, diamond guide

A Diamond Is Forever. Or At Least Really Old.

Stunning. Brilliant. Timeless.  Diamonds are a unique reminder of the singular beauty of nature. They represent eons of time under the earth, slowly growing into perfect crystals that we have learned to craft and hone into beautiful gemstones. Each diamond has certain variables in their appearance, shape, color, and level of clarity. These are commonly known as the 4 C’s.

When Grading Diamonds Began

It wasn’t until the 1950’s or so that standards were adopted by which to judge diamonds by the Gemological Institute of America, or GIA.  Before then, there were no universal metrics. The standards now used around the world today are Color, Clarity, Cut and Carat Weight.  This set of standards enabled both dealers and consumers the ability to know precisely what they were purchasing.


Diamond Cut

Many people mistake the term cut to mean the actual shape of the stone. Cut actually goes much further than that. First off, cut is about how light refracts in the diamond. In other words, it is how light is returned back to the eye with maximum scintillation and brilliance. If you were to measure the objective brightness of a diamond, i.e. all the light that is reflected inside, like a light bulb, that is brilliance. Secondly, when you see beautiful flashes of color, that is the fire of a diamond. Lastly, scintillation is essentially the sparkle effect that happens when either the observer or stone moves under a light source.

As a result, best diamonds have the proper proportions to maximize the brilliance and scintillation of the stone. It also has the ideal ratio between it’s weight and it’s diameter, thickness, and how well it is polished.

Diamond Color

The best way to describe a diamonds color is to describe it’s lack of color. A diamond’s color is measured using the GIA® D-to-Z diamond color grading system. This is the gold standard adopted the world over. The less color a stone has (as clear as a drop of water), the higher the value.

Master stones are used for calibration and comparison to determine the absence of color. Special lighting and measuring environments are used to determine the color to a high degree of precision. Ideally, this means that no matter where in the world it is measured, it will yield the same color grade. However, to the untrained eye, these differences will be very difficult to discern.

Diamond Clarity

Much in the same way that the color is graded on the lack of color, diamond clarity is graded on the lack of inclusions, or blemishes, in a stone.

Internal particles = Inclusions
External imperfections = blemishes

For the most part, inclusions and blemishes are tough to see with the naked eye. As accuracy in the grading is paramount, trained gemologists have to evaluate many factors when mapping inclusions and blemishes including the quantity, size, shape, and position of the imperfections. Here is the grading scale:

  • Flawless: No internal or external flaws 
  • Internally Flawless: Zero internal flaws, may have external flaws
  • VVS1, VVS2: Very, very slightly included: It is quite tough to see imperfections under 10X magnification
  • VS1, VS2: Very slightly included: Imperfections are not typically visible to the unaided eye
  • SI1, SI2: Slightly included: Inclusions are visible under 10X magnification and might be visible with the naked eye
  • I1, I2, I3: Included: Inclusions are visible with the unaided eye

Diamond Carat Weight

At last, we get to carat weight, or the overall size of the diamond! To many buyers, size is the most important factor in their purchase. So how is carat weight determined? It’s very simple. We weigh it.

All gemstones have what is known as a specific gravity. Read here for a cool science lesson on specific gravity. Since the specific gravity for diamonds is known, all you need is a very high precision scale to give you the exact carat weight! Nifty, huh?

We Have An Expert Gemologist

We are fortunate enough at Jewelry and Loan Pro to have the services of a GIA graduate gemologist. If you have any questions about your diamonds, or wish to buy, sell, or even get a loan on your diamonds, diamond rings, or other jewelry, we are here to help. We hope you enjoyed this guide, and we would love to hear from you!

2017-11-29T11:47:33+00:00 November 11th, 2017|Uncategorized|
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