It is known that the quality and the cost of diamonds are actually defined with four C-factors which characterize:

• Clarity - the purity or the presence of inner and superficial defects in the diamond's material;
• Color - the color or the transparency degree of the diamond's material;
• Cut - the diamond's cut form and the presence of some deviations from established standards;
• Carat Weight - the diamond's weight.

Various certification centers all over the world have elaborated evaluations criteria for these parameters and according to them the costs of diamonds are determined. However all these C-factors influence only indirectly upon the principal characteristic of a diamond - the beauty of its brilliance.

In this connection the specialists of the RFNC-VNIIEF (Sarov) and of the PC Kristall (Smolensk) have elaborated by means of a computer program for gems brilliance numeral modeling the algorithm of a general parameter determination that directly evaluates the diamond's brilliance beauty. It's suggested to name this coefficient the "Charm".

The proposed Charm coefficient is an integral characteristic describing the diamond properties in dynamics on the basis of the evaluation of brilliance films. Its value is determined by means of a special mathematical treatment of a great quantity of brilliance images sequencies at different inclinations and slewing angles of a diamond. The brilliance films can be calculated mathematically by means of a program modeling diamond brilliance or can be taken by a video-camera from a real diamond on a specially designed device.

In such way we suggest to introduce into the diamonds certification the following modifications:

• an objective diamond quality evaluation should be executed with due regard of five C-factors where the Charm coefficient must take one of the highest positions by its importance;
• the certification of the diamonds brilliance should be made by means of tools with specially designed and certified instruments.