Differences in Diamond Grading

Are all independent diamond certificates created equally..? No. Read on to find out more about the differences between the grading of the different laboratories

---

If you've delved deep enough into finding out the quality of a diamond, you'll understand that it's vital to ensure you're diamond has been independently certified. Here we go a bit deeper into the differences between the independent laboratories.

To begin, it's worth pointing out that each of our diamonds is certified by one of the following professional independent organisations:

GIA	Gemological Institute of America http://www.gia.edu/
EGL USA	European Gemological Laboratory USA http://www.eglusa.com/
AGS	American Gem Society Laboratories http://agslab.com/
HRD	Hoge Raad voor Diamant (Diamond High Council) http://www.hrdantwerp.be
IGI	International Gemological Institute http://www.igiworldwide.com

Here’s where it can get a little bit confusing. Whilst all these laboratories do a lovely job of certifying diamonds, they don’t always agree on how diamonds should be graded. They each have their own specific criteria for determining the colour and clarity grades and some laboratories are stricter than others.

The following handy tables show our experience of the differences in colour and clarity grading between the major labs, so you can more easily compare diamonds certified by different labs.

Colour Comparisons	GIA	AGS	HRD	IGI	EGL USA
Whitest	D	D
Ultra White	E	E	D
Very White	F	F	E	D	D
White	G	G	F	E	E
White	H	H	G	F	F
Very Slight Yellow	I	I	H	G	G
Slight Yellow	J	J	I	H	H

 

Clarity Comparisons	GIA	AGS	HRD	IGI	EGL USA
100% 10 x Loupe Clean	FL/IF	IF
100% 10 x Loupe Clean to the untrained eye	VVS1	VVS1	LC/LC+	IF
100% 10 x Extremely Clean with Loupe	VVS2	VVS2	VVS1	VVS1	IF
100% Very Clean with 10 x Loupe	VS1	VS1	VVS2	VVS2	VVS1
100% Eye Clean	VS2	VS2	VS1	VS1	VVS2
90% Eye Clean	SI1	SI1	VS2	VS2	VS1
50% Eye Clean	SI2	SI2	SI1	SI1	VS2
Not Eye Clean	I1	I1	SI2	SI2	SI1
Not Eye Clean	I2	I2	I1	I1	SI1

As you can see, a diamond graded as G colour, VS2 clarity by GIA is likely be graded E colour, VVS2 clarity by EGL USA.

You might be wondering, here must be an easier way to compare diamonds when the certifying laboratories can’t even agree! Don’t worry – this is why we developed our unique DiamondScore.

DiamondScore takes these grading differences into account and gives you one clear mark out of ten for each diamond, so choosing the best quality diamond couldn't be easier.

Find out more about DiamondScore here