How To Grade A Diamond

Diamond grading sometimes seems a little scary, but it doesn’t have to be.

You may have even heard of the five areas that are mainly focused on, also known as “The 5 C’s.”

These are:
diamond-stone

  • Clarity
  • Color
  • Cut
  • Carat
  • Cost

From these five items you can determine the quality of any diamond.

Clarity

Diamond Clarity Chart

Diamond Clarity Chart

Clarity of a diamond is broken down into six grades. They include (in order of best to worst):

Flawless (FL) – Flawless, no inclusions to be found under 10X magnification. No surface blemishes.

Internally Flawless (IF) – Internally Flawless, no inclusions to be found under 10X magnification. Some small surface blemishes are present.

Very Very Slightly Included  (VVS) – Very, Very small inclusions, very difficult to see with 10X magnification. VVS 1 is a higher grade than VVS 2.

Very Slightly included (VS) – VS1 and VS2  have very small inclusions, difficult to see with 10X magnification.

Slight Included (SI) – SI1 and SI2 have small inclusions, easy to see under 10X magnification but not visible to the naked eye through the top of the stone. SI3 have small inclusions, very easy to see under 10X magnification, but visible to the naked eye only by a trained professional.

Imperfect (I) – I1: Inclusions are hardly recognizable to the naked eye. Does not affect brilliance. I2: Larger or more numerous inclusions fairly easy to see with the naked eye and slightly diminishing brilliance. I3: Large and/or numerous inclusions very easy to see and diminishing brilliance. Sometimes detrimental to the integrity of the stone itself.

Color

Diamond Colors

Diamond Colors

The color scale goes by the alphabet starting at D and going to Z. D-E-F are colorless, G-H are still considered clear white stones. I-J are white but starting to draw a very small amount of color. K-L are starting to draw noticeable color. Below L the color tint is very noticeable and continues to hurt the value of the stone until the color becomes so saturated that it becomes a fancy colored diamond (fancy color diamonds can sell for unbelievably high dollar amounts).

Cut

Diamond Cut Diagram

Diamond Cut Diagram

The cut of the diamond not only refers to it’s shape but also to it’s width or diameter, it’s length, it’s depth, and all of the angles and degrees of every outside line and every facet. How well the stone was polished will also fall under the cut grade.

Examples of Diamond Cuts

Examples of Diamond Cuts

 

The better the cut, the more brilliant the stone will be, hence the better it will sparkle. Although a very extensive part of grading, a true professional will know a good cut from a poor one and should be able to explain the differences to the consumer.

Carat

Diamonds are measured by a weight measurement known as carats. 1 full carat equals approximately .20 gram. Carats are then subdivided into a smaller weight measurement known as points. There are 100 points in a carat. Therefore a 1/2 carat diamonds would weigh 50 points. However, law only requires a 1/2 carat to weigh between .46 carat and .54 carat. So it’s good to always know the exact points.

Cost

All of the factors above combined with supply and demand will determine the cost of a diamond.