If you’ve ever looked for a diamond to buy, perhaps you’ve come across the widely used color grading scale of the GIA (Gemological Institute of America). And you may have also heard that there is the so-called Argyle color grading scale. Let’s see what this scale is and how it compares to that of the GIA.
What Is the Argyle Diamond Grading Scale?
The Argyle color grading scale was created by the Argyle Diamond Mine as a tool to be used in evaluating the stones found there.
The Argyle Diamond Mine is located in Australia and is one of the largest diamond suppliers in the world.
It is worth noting that most of the natural pink diamonds sold worldwide are mined there.
The mine is also a significant source of brown and blue diamonds.
The Argyle color scale was created to grade mainly pink diamonds, but it also contains grades for pink-champagne and blue-violet stones.
What Are the Color Grades on the Argyle Scale?
Pink diamonds are graded on the Argyle scale using numbers from 1 to 9, and each number is followed by an abbreviation denoting the color variation of the stone.
For example, the grade 5PP means that the stone is purplish pink and its color is graded 5, i.e., in the middle of the scale.
On the Argyle scale, lower grade numbers represent higher intensity of pink color. For example, a stone graded 1P will have a more saturated pink color than a diamond graded 9P.
The exceptions to this rule are the grading scales for pink champagne and blue violet stones: For these colors, a higher number represents a more saturated hue.
Here are the grades used for each color variation on the Argyle scale (from low to high color intensity):
- Purplish Pink: 9PP to 1PP
- Pink: 9P to 1P
- Pink Rose: 9PR to 1PR
- Pink Champagne: PC1, PC2, PC3
- Blue Violet: BL1, BL2, BL3
How Is the GIA Color Scale Different from the Argyle Standard?
Unlike the Argyle scale, the GIA color scale is meant to evaluate white diamonds, not colored ones. At the top of the GIA scale are the perfectly white, or colorless, stones.
The lower you go down the scale, the more visibly tinted the diamonds become.
Here is a quick summary of the color grades on the GIA scale:
- Colorless: D, E, F
- Near Colorless: G, H, I, J
- Faint Yellow: K, L, M
- Very Light Yellow: N, O, P, Q, R
- Light Yellow: S to Z
How Are Colored Diamonds Graded on the GIA Scale?
So, if the GIA scale was created for white diamonds, isn’t there also a scale that could be applied to colored stones?
The answer is yes: The GIA has a separate scale for fancy-color diamonds, and it is actually more universal than the Argyle scale.
Whereas the Argyle grades are mainly meant for variations of pink, the GIA colored-diamond scale can be applied to any color.
Here are the GIA grades used to evaluate fancy-color diamonds (from low to high color intensity): Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark, and Fancy Deep.
To assign a grade to a particular stone on this scale, the diamond’s hue is determined and its name is added to the grade denoting its intensity.
For example, if a pink diamond’s hue has been judged as Fancy Intense, the stone’s grade will be Fancy Intense Pink.
If the same stone has a secondary undertone that is brown, for example, its grade will be Fancy Intense Brownish-Pink.