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Paul-Antwerp
09-26-02 08:16 PM I did not have a lot of time to catch up with DT lately, but I took an hour to read this thread thoroughly. Honestly, I am amazed, and I do not understand how great professionals and scientists like Bill, Gary and Serg can get into such a crazy argument, without anyone seeing that the whole discussion is pointless. You have been arguing all this time, about a point made by Sergey, that basically never happens in the process of cutting diamonds. I will first explain Sergey's point again. To take the pavillion angle, it should be measured compared to the straight girdle plane, but it is measured compared to the table. So, if the table is tilted, a pavillion without variance would be measured as one with enormous variance. Hence, we cannot trust the measurement, and we should only rely on the angles of opposite pavilions. Now, how are diamonds cut, especially the pavilion? Well, they are put into a dop, based upon the table, and each angle is cut on the basis of that table. Of course, there is a concept of tilted tables while cutting. It happens at this point in the process: a stone is blocked, and then, it is checked whether the culet will come out, and whether tilting the table is necessary in order to maintain the highest weight with the same cut. After tilting the table, the pavilion is finished, never before. So, the high precision of cutting the pavilion cannot be disturbed by tilting the table afterwards. Basically, this makes the whole point of Sergey, and his testing-proposal pointless, as you will be testing something that does not happen in the world of cutting. Guys, can I ask you next time, before you get into such an argument, to come and ask me what I think about a certain theory. I think that a lot of time and distress could be avoided that way. Live long,
rockdoc
09-28-02 12:45 AM NO!!!!!!!!!!!!!!! Garry I've already said I see no purpose to this. I DO NOT wish to participate. There is no reason to prove to you that I know how to evaluate stones. In addition, from what I understand of this, you've chosen to ignore what I have said about what I can see. I do not know your motivation but I am sure there is one.... it will surface once those who do participate in the picnic figure it out. Rockdoc
09-29-02 10:28 AM Guys, can we put all machoism aside, and go back to the basics. It starts to resemble a bet in a bar after too many drinks, and certainly not a useful discussion. The basics is this: the table of a brilliant can be compared to the foundation of a house. Like one cannot start building without a foundation, one cannot start cutting without first putting the table facet. The whole stone is based on that table, so definitely, the preciseness of the pavilion. Now, it is possible, that in the course of cutting, the table is adapted, and one of the possible adaptations is slightly tilting the table. However, this is done after blocking the stone, and after it is established that one gets a better result (pointed culet, or avoiding an inclusion) by tilting the table. But the final pavilion will then be based upon that new tilted table, so if all work is done well, it will be straight again. The issue here is, that one can trick the Sarin-measurement, by tilting the table after the whole stone is finished, which will result in a bad looking measurement, while the stone will still look the same. I agree, that this would happen, but no cutter in his right mind would do that. I suppose that you would agree that most cutters know what they are doing. Likewise, you would agree that they would cut for the highest financial gain. Now, suppose that this nice H&A is finished, and there is a slight inclusion at the side of the table, that can be cut away by tilting the table. First, the cutter must have made a mistake previously, because he could have foreseen this after he put the original table facet. Now, he needs to correct his mistake. He can tilt the table, but he knows that he risks his H&A-pattern, and a lower symmetry-rating from the labs. That means that he will only tilt the table, if he has room to re-cut the whole stone. Another option is lowering the table, without changing the inclination, and in that way, he only needs to re-cut the crown. If he would just stick to tilting the table, without re-cutting other parts of the stone, and if this would result in just a Good-symmetry-rating of GIA (like Gary claims that his stock has 10-20% of these stones), then the current sales value of this stone would be badly affected. This makes no sense for the cutter. Of course, sometimes, people do things that make no sense. To me, this whole discussion is a perfect example. But if this starts to hurt in your wallet, I think that you will think twice. Live long,
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© 2002 Sergey Sivovolenko, Yuri Shelementiev
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