Diamond Education


Making the decision to buy a diamond can be an exciting but daunting task. What should you look for? What determines the price? Have you heard people refer to the 4Cs of diamonds, but have no idea what that means?

Here at Unique Celtic Wedding Rings, we hope to clear up some of the confusion and help you feel much more confident, in selecting your perfect diamond.  

Diamonds can vary greatly in quality and price. During the 1940’s and 1950’s the GIA (Gemological Institute of America) developed a universal grading system and thus -- the standards for the 4Cs were born; carat, color, clarity, and cut. According to the GIA.edu website, “GIA's mission is to ensure the public trust in gems and jewelry by upholding the highest standards of integrity, academics, science, and professionalism through education, research, laboratory services, and instrument development.”


Diamonds and other gemstones are measured in weight by carats (one carat = .2 grams). It is important to note that carat, is not the same as karat, which instead refers to gold purity.

Diamonds are divided into points. This is easiest to understand, if you think of it like pennies on a dollar. A one carat diamond is 100 points, so a 25 point diamond weighs .25 carats. The weight of a diamond does play a big role in the cost of a stone. However, two diamonds - weighing exactly the same - can carry very different price tags, depending on the other Cs.


Color - or more significantly the absence of color - is very important in determining a diamond’s quality. GIA’s color grading chart starts at D which is colorless and goes all the way to Z.

D, E, F – Colorless Stones

G, H, I & J – Near Colorless

 K, L, & M – Faint Yellow

 N-R – Light Yellow

 S-Z  – Yellow

The GIA has a clearly defined range of color appearance.  Diamond color is graded by comparing them to diamonds - in which the color has already been defined - under lighting and conditions which are deemed suitable by industry standards. A very slight variation in color can make a tremendous difference in the value of a diamond, so if you are hoping for a certain weight of diamond, but need to stay within a definite price range, you may be able to sacrifice on color a little, to get what you want.


 Clarity is determined by the lack of blemishes or inclusions found in a diamond. A nice term for these imperfections are, “birthmarks” since they are produced as the stone is being formed.

 The GIA clarity grades are:

Flawless (FL): No inclusions or blemishes are visible under 10X magnification.

Internally Flawless (IF): No inclusions but a few blemishes are visible 10X magnification.

Very, Very Slightly Included (VVS1 and VVS2): Inclusions are difficult to see under 10X magnification.

Very Slightly Included (VS1 and VS2): Minor inclusions visible under 10X magnification.

Slightly Included (SI1 and SI2): Inclusions are visible under 10X magnification.

Included (I1, I2, and I3): Inclusions are obvious under 10X magnification and may affect the transparency and brilliance of the cut diamond.


 The cut of a diamond can have a big impact on the brilliance of the stone. A diamond that is cut too shallow or too deep, can affect the way light reflects upon each facet. A poorly cut a stone may have dull or dark areas of a stone where the light just can’t reach.

The cut of a stone is graded as;

Very Good

The quality of cut is based upon; brilliance (the total light reflected from a diamond), fire (the dispersion of light into the colors of the spectrum), and scintillation (the flashes of light, or sparkle, when a diamond is moved).

When you select a diamond engagement ring from us, we want you to know that you have the freedom to choose the diamond that is right for you. Because diamonds can vary so much in quality and price, we are always happy to change out stones, or do whatever it takes to meet your diamond needs and expectations.

Mary Comerford