1. D, E, F -These are the whitest diamonds, colorless and are often called “collection” diamonds. The difference among them is the transparency and clarity of the color. Other nick names for these diamonds are: River. When you want to note that the diamond is so white, that it looks whiter than D color, it is called a Golkonda diamond, after the Golkonda region that was the main diamond supplier in the world from the 4^th century until 1730. Today they are found in a very small amount in different mines. These diamonds are of a kind which is called: Type 2A. These are diamonds that have no Nitrogen in them. The GIA issues a special certificate for them.
2. G, H – These stones have a very slight hue of yellow (or gray or brown).
3. I, J – These stones have light to medium hue of yellow (or gray or brown).
4. K, L – These stones have a strong hue of yellow (or gray or brown).
5. M, N – These stones have a very strong hue of yellow (or gray or brown).
6. N – Z – Any stone which is more yellow than N and less yellow than Z is called CAPE or DARK CAPE, after the Cape region in South Africa, where the rush for diamonds began in 1869. These are the cheap colors, and are sold with no list. The GIA grades them between 2 color grades. For instance: W-X or Y-Z range.
7. Fancy Yellow – Any stone which is more yellow than Z is called Fancy Yellow and its value is higher.

Diamonds with a brown hue:

G – H colors with a brown hue are called in the diamond market: TTLB – Top Top Light Brown. These diamonds show brown hue through the pavilion but look white through the crown.

I – J colors with a brown hue are called in the market: TLB – Top Light Brown. These diamonds show a slight brown hue also through the crown.

K-L-M colors with a brown hue appear in the GIA certificate as: Faint Brown

N-O-P-Q-R colors with a brown hue appear in the GIA certificate as:

Very Light Brown

S-T-U-V-W-X-Y-Z colors with a brown hue appear in the GIA certificate as:

Light Brown

Rules regarding selection of Master Stones

1. All of the master stones should be in the same border of color range.

D+ D D-  E+ E E-  F+ F F-  G+ G G-  H+ H H-  I+ I I-  J+ J J-  K+ K K-  L+ L L-

High border of color range series:

Low border of color range series:

Two color range series:

2. The master stones should be over 0.30 carat, and 0.50 carat is preferred.
3. The master stones should be of VS2-SI2 clarity grade.
4. The master stones should not be fluorescent.
5. The master stones should not be cloudy.
6. The master stones should have only yellow hue (not brown or gray).
7. The master stones should be of a good cut.

Rules regarding checking color

1. Check color in a white environment.
2. Check color under a “daylight” fluorescent lamp.
3. Check color against a clean white piece of paper.
4. Clean the stone.
5. Place the stone with the crown facing down on the color paper and check the color concentrations in the culet and on the sides of the girdle. The color checking is done from the pavilion, since round stones start to show color from the crown only from I, J colors.
6. It is better to check the color in the morning (before noon).
7. You can blow gently on the stone. This masks the stone’s brilliance and emphasizes its color.

Rules regarding working with Master Stones

1. Compare the color concentration of the stone to the color concentration of the master.
2. Keep a slight gap between the master stone and your stone in order to prevent an optical illusion of color transmission.
3. You should check the color of the stone once from the left side of the master and once from the right side of the master-“Master eye effect”.
4. You should have inner certificates for the master stones for identification.