Introduction to the 4 C's

Clarity:

Few things in nature are absolutely perfect.  That's as true of diamonds as anything else.  Diamonds have internal features, called inclusions, and surface irregularities, called blemishes.  Together, they're called clarity characteristics.  Clarity is the relative absence of inclusions and blemishes.  Among other things, blemishes include scratches and nicks on a diamond's surface. Inclusions are on the inside, or they might extend into the interior from the surface of the stone.

The GIA clarity scale includes eleven diamond clarity grades.

Flawless, Internally Flawless(IF), Two categories of Very Very Slightly Included( VVS1 and VVS2 ), Two categories of Very Slightly Included(VS1 and VS2), Two categories of slightly included(SI1 and SI2), Three categories of Included( I1, I2, I3).

Flawless diamond shows no inclusions or blemishes under 10X magnification.

Internally Flawless (IF) diamond shows no inclusions under 10X magnification.

Very Very Slightly Included ( VVS1 & VVS2) diamond contain minute inclusions that are extremely difficult to see under 10X magnification.

Very Slightly Included (VS1 & VS2) diamond contains small or minor inclusions under 10X magnification

Slightly Included (SI1 & SI2) diamond contains inclusions that are noticeable under 10X magnification.

Included ( I1, I2, I3) diamonds that fall into the I range contain inclusions that are obvious under 10X magnification.

Color:

People outside the diamond trade often misunderstand the relationship between diamonds and color. Many people think of diamonds as colorless. In reality, truly colorless diamonds are quite rare. Most diamonds used in jewelry are nearly colorless with yellow or brown tints--most often light yellow. Diamonds come in many colors other than yellow and brown. Some of the most rare colors are red, purple, and green. With colored diamonds, more color usually means higher value, so the brightest, purest colors are the most desirable.

GIA Color Scale is the most widely used diamond color-grading system in the world, and the normal color range of diamonds is often called the "D-to-Z scale."

D-E-F is colorless

G-H-I-J is near colorless

K-L-M is faint

N-O-P-Q-R is very faint

S-T-U-V-W-X-Y-Z is light

The letters in the D-to-Z scale don't describe actual colors, or hues. Each letter actually represents a range of color that's based on a combination of tone-darkness or lightness--and saturation--intensity. The combination is called depth of color, and it's a measure of how noticeable a color is.

Cut:

When you think of the cut, you probably think of the shape of the diamond.  You are partially correct.  While cut does refer to shape, it also refers to the proportions of how the diamond is actually cut.

Diamonds are cut into many different shapes, reflecting not only popular taste but the proportions and quality of the rough diamond. The most popular shapes include Round, Oval, Square, Princess, Emerald, Baguette and Marquise cuts,  Many specialty shapes are also available.

A diamonds overall proportions, as well as the size and placement of its many reflective surfaces or facets play a large part in "cut".  The consistency and balance of these can greatly affect how the stone captures light and reflects it back to the eye.

Your best cut grades are Ideal, Excellent and Very Good,

Carat Weight:

The size of a diamond is measured, not by its dimensions, but by weight.  One carat, the traditional unit of measure for diamonds, is equal to approximately 0.2 grams.  You may also hear the weight of a diamond referred to in points.  A point is equal to 1/100 of a carat; therefore, a 75-point diamond equals 0.75 carat.  Diamonds of equal weight may appear slightly different in size, depending on their depth and proportions. Because they are quite rare, larger of gem quality are much more valuable.