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Royal Coster
Diamonds Size
MM / INCH (Circumference)
48 / 1.89 48 4½ 8
49 / 1.93 49 9
50 / 1.97 50 K 10
51 / 2.01 51 L 11
52 / 2.05 52 6 12
53 / 2.09 53 13
54 / 2.13 54 14
55 / 2.17 55 O 15
56 / 2.20 56 P 16
57 / 2.24 57 8 17
58 / 2.28 58 18
59 / 2.31 59 R 19
60 / 2.36 60 9 S 20

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Royal Coster Welcomes Baby Koi Diamond - Royal Coster Diamonds

Royal Coster Welcomes Baby Koi Diamond

About ten years ago, people found an unusual diamond in Congo. The diamond was not only special because of its size, of over 60 carat, but mainly because of its color. Diamond scholars and experts examined the diamond. But they did not really know what to do with this stone.

The diamond was rare and valuable, that was clear. But nobody ever saw a diamond like this. Therefore, it was difficult to determine the value of the diamond. The experts decided to call the stone 'the Koi Diamond'. They named it after the well-known fish. The fish symbolizes happiness, prosperity and perseverance and is white-orange in color. This name suits the stone perfectly.

diamond polisher at coster finds koi diamondBeautiful damage

The Koi Diamond is white on the outside, but orange on the inside. During the natural process in which the diamond is formed, a piece of nitrogen remained inside the diamond. The nitrogen has an orange-like color. Normally, particles of nitrogen in diamonds are hardly visible. If they are even visible at all. But besides the nitrogen, there is also a crack in the crystal lattice of this diamond. Normal damage causes the incoming light in a diamond to disappear. But in this case, it created something beautiful. The damage ensures that the light reflects in such a way that the diamond shines orange. But orange is not the only color. The beautiful damaged diamond can also shine yellow, blue and black. The Koi is a rare gift from Mother Nature.

royal coster koi diamond in polishing tool and singleCoster's Baby Koi

A little while ago, one of our master polishers was busy polishing a brilliant. But suddenly he noticed that the stone in his grinding tongs turned orange. It appeared he was holding a small version of the Koi Diamond. Our polisher finished cutting the diamond in a perfect brilliant shape. Now you see the special phenomenon of orange brilliance even better.


You can admire (and buy) the Baby Koi, as we call him affectionately, at Royal Coster Diamonds. Please contact a diamond consultant for more information.

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