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Diamond Education

It's all about the 4Cs

It has been said that diamonds are like snowflakes in that no two are alike. Each stone is unique in its beauty and properties with variations in colors, inclusions and trace elements. Using the GIA Standard, we can value diamonds based on Color, Cut, Carat Weight and Clarity.

Diamond Anatomy

There are five main features of the diamond’s basic anatomy. They are the table, crown, gridle, pavilion and cutlet and they define your diamond’s shape, size and its overall beauty and brilliance.

Diamond Cut

Diamond cut refers to how the diamond is physically cut from the rough stone. While nature determines color and clarity, the diamond cutter determines optimal cut for the maximum yield of carat weight. Cut does not refer to shape (round, pear, oval etc.), but rather the symmetry, proportions and polish of a diamond.

This is the main factor in determining the diamond’s overall appearance, based on brilliance (the brightness to the eye created by white light reflections from the surface and inside), fire (the dispersion of light into the colors of the visible spectrum as seen in flashes of color) and scintillation (sparkle when the diamond is in motion).

Cut effects appearance. The better the diamond’s cut, the more brilliant and vibrant and the bigger it looks.

Click on the cut grade to learn more

  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor


This is sometimes confused with cut, but it is the outline of the diamond. In order to maximize a stone's material properties, a cutter may choose from various shapes, each with their own aesthetic and cutting requirements.

Round Brilliant


Oval Brilliant


Cushion Brilliant


Pear Brilliant


Princess Cut


Marquise Brilliant


Heart Shaped


Emerald Cut


Baguette Shaped


Radiant Cut


Asscher Cut


Trillion Cut


The most popular shape is the round brilliant. It’s facets and features yield the maximum amount of light, setting the standard for most brilliance and beauty. All other shapes are referred to as “fancy cut” and offer unique beauty and appeal.

? Did you know: The practical history of diamond cuts can be traced back to the Middle Ages, while their theoretical basis was not developed until the turn of the 20th century. Design creation and innovation continue to the present day and Market Street Diamonds employs the most innovative technology—notably laser cutting and computer-aided design—for cuts that maximize optical performance and minimize waste reduction. Thus, giving you the best quality and value.

Diamond Color

Clear diamonds range in color shades. The letter values D, E, and F are almost perfectly clear. Letter values G-Z are more yellowish. The lower the letter, the more yellow you’ll see.

  • Colorless
  • Near Colorless
  • Faint
  • Very Light
  • Light

Diamond Carat

Diamonds are sold by the carat (shown as ct.), which is actually a unit of weight, though most think of a carat in terms of size. The word "carat" comes from the "carob" seed, the original unit of measure for diamond traders. Today, a carat is equal to exactly 0.2 grams (about the weight of a paper clip). Carat weight is unrelated to the similar sounding karat, which refers to gold's purity.

3.00 ct

9.75 - 9.85 mm

Approximate Average Size

Diamond images are for reference only and may vary based on screen size

Diamond Clarity

When we talk clarity, it’s exactly that: a diamond’s transparency. The sharper the clarity, the better the stone.







Flawless Diamonds (FL)

The highest clarity grading for diamonds. The diamond shows no inclusions or blemishes when viewed under 10X magnification.
Clarity of a diamond is its relative freedom from inclusions and blemishes. A relative scale from flawless to included is used for clarity grading.

Internally Flawless Diamonds (IF)

The diamond is internally flawless with no inclusions. Only insignificant blemishes are visible under 10X magnification. Internally Flawless (IF) diamonds are very rare and valuable.

Clarity of a diamond is its relative freedom from inclusions and blemishes. A relative scale from flawless to included is used for clarity grading.

Very Very Slightly Included Diamonds (VVS1, VVS2)

Inclusions are difficult for a skilled grader to see under 10x magnification. VVS1 inclusions are typically only visible from the pavilion, while VVS2 inclusions are visible from the crown. In each, the inclusions are invisible to the eye, appearing identical to the higher grades unless viewed under 10x magnification by a skilled grader.

Very Slightly Included Included Diamonds (VS1, VS2)

Inclusions are clearly visible under 10x magnification but can be characterized as minor. Inclusions are not visible to the naked eye. Perhaps 1 in 100 untrained observers can detect VS2 inclusions with the naked eye, on close inspection under ideal conditions.

Slightly Included (SI1, SI2)

Inclusions are noticeable to a skilled grader using 10x magnification. SI1 is the lowest grade with flaws often invisible to the naked eye. SI2 inclusions are usually visible to the naked eye, although they will require close inspection.

Included (I1, I2, I3)

Inclusions are obvious under 10x magnification and may affect transparency and brilliance. I1 diamonds have inclusions that are almost always visible to the naked eye. Because I2-I3 diamonds have prounounced inclusions, and in the case of I3 may even affect the diamond's durability, they are not offered by Lumera.