Colour
In Russia there is a state system of diamond grading (Factory standart 117-4.2099-2002. Polished diamonds, Technical conditions. Classification). It is no secret that Kristall’s and GIA’s standards are not in close agreement in definition of colour. There is a comparison.
| Factory standart | GIA | Description | ||
 |  | |||
 | 1 | 1 | D | Colourless higher, as well with a blue tint |
 | 2 |
E
|
Colourless
| |
 | 2 | 3 |
F
|
With a subtle yellowy, greenish, violet and grey tint
|
 | 3 | 4 |
G
|
With a slight yellowy, greenish, violet and grey tint
|
 | 5 |
H
|
With a slight yellowy, greenish, violet and grey tint, with a light brown tint as well
| |
 | 4 | 6 | I | With a visible yellow, green and gray tint |
 | 7 | J | With apparent yellow, green, lemon and gray tint | |
 | 5.1 | 8.1 | K | Very weakly yellow coloured tint, very lightly yellow tint with a slight gray one as well |
 | 5.2 | 8.2 | L | A weakly yellow coloured tint, a lightly yellow tint with a slight gray one as well |
 | 8.3 | M | A light yellow coloured tint with a slight gray tint as well | |
 | 5.3 | 8.4 | N-O | A light-yellow, a light-yellow with a slight gray tint as well |
 | 8.5 | O-Z | Yellow, as well yellow with a slight gray tint | |
 | 6 | 6.1 | I-J
TLBr | With a visible brown tint |
 | 7 | 9.1 | K
LBr | Weakly coloured brown |
 | 9.2 | L-M
LBr | Lightly coloured brown | |
 | 9.3 | N-O
Br | Brown | |
 | 9.4 | P-Z
DBr | Dark-brown, black | |