Guide to Sapphires Grading: Color, Clarity, and Cut

Grading Natural Sapphires.

Unlike diamonds which rely on no color for their value, sapphires along with almost all gemstones are graded and valued on color. I read a few articles and blogs which try to sell the AAA down to B as a way to not only grade a sapphire but also create its value? This grading is not only inaccurate but also very misleading to the consumer.

Below I will explain how sapphires are graded and valued taking 4 main factors into account (Hue, tone, saturation & carat weight). With the AAA to B grades really doesn’t take any one of these factors into account, as a result, you not left with any real way of determining how that sapphire value was created. We will start on the color, also known as the “Hue”, the GIA gemstone grading for color is the one of the best ways to grade and understand how a sapphire should be graded.

This sapphire is a rare natural color change, taken-on two GIA color grades.Hue,To start with, a sapphires overall color or hue, as an example, if the sapphire is a pure blue then the code/grade for this gemstone would be given as a “B” referring to blue. Now if this sapphire carries a secondary color with a slight undertone of violet then the sapphire grade would change to “vB” referring to violet blue. (If blue was still the predominant color) If by chance the violet was a stronger hue than blue the grade would change to “bV”. Below I added a color chart showing not only the different colors sapphires come in but also how they graded for the “Hue“ and the initials used for giving the GIA color grade.

Hue Table

The GIA Colored Stone Grading System includes a description system that uses 31 hue names to describe

colored gemstones.Here we show the color chart which coves all colors sapphires can be found in.

Name	Code	Color
very slightly greenish blue	vslgB
Blue	B
violetish blue	vB
bluish violet	bV
Violet	V
violetish purple*	vP*
Purple	P
reddish purple	rP
red-purple or purple-red	RP/PR
strongly purplish red	stpR
slightly purplish red	slpR
Red	R
orangy red	oR
red-orange or orange-red	RO/OR
reddish-orange	rO
Orange	O
yellowish-orange	yO
orangy yellow	oY
Yellow	Y
greenish-yellow	gY
yellow-green or green-yellow	YG/GY
strongly yellowish green	styG
yellowish-green	yG
slightly yellowish green	slyG
Green	G
very slightly bluish-green	vslbG
bluish-green	bG
very strongly bluish	vstbG
green-blue or blue-green	GB/BG
very strongly greenish blue	vstgB

Tone,Second comes the the sapphires “Tone “, tone measured on a scale from numbers 2 to 8, a sapphire graded as a 8 would be very dark & unlikely to be a transparent gemstone, with low market value.About 80% of blue sapphires full under this grade, sometimes referred to as very dark blue to almost black, we’re as a sapphire graded as a 2 would be almost off-white with slight hint of blue. Royal blue sapphire would typically carry a 6 for tone, with vivid blue to cornflower blue carrying a 5. This natural blue sapphire ring, this sapphire carries a GIA gemstone grade of GIA B 5/4.

I have added the GIA tone scale below to see how tone is measured, this helps explain how the GIA grade is given.

Name	Scale	Tone
very light	2
Light	3
medium light	4
Medium	5
medium dark	6
Dark	7
very dark	8

Saturation, Next comes the sapphire saturation or how bright the color is, the saturation plays an equal role in a sapphires value, sapphire graded with a saturation of 4 to 6 will carry the highest value. As a example, a perfect royal blue sapphire would carry a saturation level of 5 were as a cornflower blue sapphire would carry a saturation of 4.Below we show two loose sapphires, the first is a royal blue sapphire carrying the GIA color grade of GIA B 6/5 with the second sapphire carrying the GIA color grade of B 5/4.

Here is a chart which shows the level of saturation for gemstones and how they are graded in blues as well as reds for rubies, when the saturation drops below a 4 the sapphire will take on a slightly grayish hue and the value will drop.

Name	Cool Color	Scale	Warm Color	Name
grayish		1		brownish
slightly grayish		2		slightly brownish
very slightly grayish		3		very slightly brownish
moderately strong		4		moderately strong
strong		5		strong
vivid		6		vivid

Carat Weight The last factor to look at for the sapphire value is the carat weight, just because a sapphire carries a high carat weight doesn’t mean that the sapphire is valuable, the sapphire value will be created on a hue, tone, and saturation first. Once the grade is given then the value will be multiplied by the sapphire carat weight. A sapphire in a dark blue with the GIA color grade of GIA B 8/7 with a carat weight of 4.00 cts might carry a value of $300.00 per carat, were as the same size sapphire which carries a color grade of B 6/5 or royal blue could easily be valued at $3,000 upwards per carat. These prices given are for natural sapphires, sapphires which are synthetic or chemically enhanced and carry very low values, often not more than $50 to $100 per carat. I hope this information is helpful on how a sapphire should be graded and why using this system is important to the value of the sapphire you looking at. For more information on natural sapphires and our sapphire engagement ring contact us at 727 797 0007 or visit us at https://www.sapphirerings.org/

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