T.L.T.Diamond - продажа и производство сертифицированных бриллиантов оптом и в розницу
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Diamonds cutting

In 1919 Marseilles Tolkovsky published his “Diamond Design” in which analyzed a course of a light beam in a brilliant. In this book he accepted a round brilliant with 57 facets as the most common model. Tolkovsky calculated corners and proportions at which the stone is characterized by the maximum game and shine: the size of a table – 53 %, a crown corner – 34,5 degrees, a pavilion corner – 40,75 degrees. The given calculations well coincided with parameters of existing brilliants which Tolkovsky believed very good polished.

Since this a brilliant with parameters Tolkovsky was considered as the ideal. However as cutters  eager to keep the weight of a stones by all their best, they always didn’t follow his parameters. In the second half of the XX century special systems of diamonds estimation were created  and it became clear, that cutting is the most difficult characteristic of a stone to be estimated. To systematize an approach to system of cutting’s estimation they began to estimate on components: to polishing, symmetry and proportions. So, each of these parts has its own grade. The quality of polishing determinates by search of external characteristics and further definition of their location, the sizes, etc. As to symmetry, it is considered that any deviation of a pattern (ornament) of a brilliant from visually symmetric reduces the quality of cutting. Proportions are estimated differently. One of approaches to an assessment of proportions (GIA) is that corners and the sizes aren't estimated but only are mentioned in the report. Other approach to an assessment of proportions (AGS, HRD) represents definition of ranges of proportions in which quality of cutting  will be considered as an identical. For different ranges appropriate classes of quality of cutting or the description ("good", "very good" etc.). In total in the world there are more than 20 various systems of an assessment of brilliants, and all of them suggest various proportions to consider the best, the unequivocal opinion at present doesn't exist.

Stone of ideal cut has triple excellent designation, and as one more name – «heart and arrows», because at monochrome lighting it gives picture of hearts and arrows. If parameters of cutting aren't sustained with sufficient accuracy, to see this drawing it will be impossible. Now to see this effect experts use the special device – firescope.

We can see arrows at a view of a table and a brilliant crown  and hearts – in case we will consider a brilliant from outside culet.