Diamonds as a mineral

Since appearing on world markets over 50 years ago, Russian diamonds have been highly sought by customers. There are three main reasons for the high value placed on our product.

First, Russian rough diamonds contain a high proportion of regularly-shaped crystals. This gives clear advantages to diamond manufacturers, who want to create ideally-proportioned polished stones.

Second, Russian diamonds are considered to be among the world’s best for color. Our rough diamonds offer greater prospects of manufacturing exceptionally white diamonds than stones from any other source.

Third, Russian diamonds are widely recognised as being the best choice for cutting and faceting. Diamond manufacturers with many years of experience agree that diamonds from Russian mines possess such unique morphological characteristics, enabling them to reduce process costs and times.

To guarantee the authenticity of each product, every ALROSA diamond undergoes a testing gemmological examination, resulting in a unique certificate or diamond grading report.

Carat Weight

All else being equal, a heavier diamond is a more expensive diamond. We use special scales to weigh diamonds, and the approximate weight can also be estimated based on the stone’s diameter. Diamonds are weighed using the traditional carat system. Of course, weight is only one element of valuation. Clarity, color and cut are also crucial.

Weight to Size Ratio

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Color

Diamonds are graded from colorless to yellowish-brown. The process involves comparing a diamond with a set of master stones, then assigning it a grade according to a set scale. The internationally recognized GIA (Gemological Institute of America) grading system uses letter symbols from D to Z for color denomination. The Russian grading standards system uses numbers from 1 (colorless) to 9 (brown).

< or equal to 0.29 ct Equal to 0.30 ct or > GIA Description
1 12 DE Colorless (exceptional white)
2 3 F Colorless (rare white)
3 45 GH Near colorless (with the slightestdiscernible hue of gray or yellow)
4 67 IJ Near colorless (slightly tinted white)
5 8 (1-5) K-L Faint yellow
6 6 (1) M-N Very light yellow
7 9 (1-4) O-RS-Z Light yellow to Strong yellow

Clarity

Clarity is the degree of absence (or presence) and the visual appearance of internal characteristics called inclusions, and surface defects called blemishes. Clarity is measured using a clarity grading scale. The smaller the number, the greater the clarity.

< or equal to 0.29 ct Equal to 0.30 ct or > GIA Description
1 1 IF Internally flawless (loupe clean, i.e. no inclusions and only blemishes are visible to a skilled grader using 10x magnification)
2 2 VVS1 Very-very slightly included (inclusions are difficult for a skilled grader to see under 10x magnification)
3 3 VVS1
4 4 VVS2
4 5 VS1 Very slightly included (inclusions are clearly visible under 10x magnification, but can be characterized as minor)
5 6 VS2
5 7 SI1 Slightly included (inclusions are noticeable to a skilled grader using 10x magnification)
5 7a SI2
6 8 SI3
6 9 I1 Included (inclusions are noticeable with less than 10x magnification, and may affect transparency and brilliance)
7 10 I2
8 11 I3
9 12 I3

Cut

Cutting allows a diamond to reveal its maximum brilliance, fire and sparkle. This is achieved by cutting a rough stone so that it becomes a faceted gem of regular shape and proportions. The most traditional shape is round brilliant.

A diamond’s shape and proportions, together with the quality of its cut and polishing, have the greatest influence on its fire and sparkle - and so, on its value.

Elements of Diamond Cut

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Cut Shapes

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This page was last updated on 27 August 2013 at 14.08