Book/Printed Material Diamond design,
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Image 2 of Diamond design,
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 3 of Diamond design,
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 4 of Diamond design,
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 6 of Diamond design,
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 7 of Diamond design, DIAMOND DESIGN A STUDY OF THE REFLECTION AND REFRACTION OF LIGHT IN A DIAMOND BY MARCEL TOLKOWSKY B.Sc, A.C.G.I. WITH S7 ILLUSTRATIONS Xon^on: E. F. N. SPON, Ltd., 57 HAYMARKET, S.W. i…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 9 of Diamond design, CONTENTS INTRODUCTION PAGE 5 PART L- -HISTORICAL 8 II.- -OPTICAL 26 III.- -MATHEMATICAL 53 The Rose 59 The Brilliant 64 A. Back 64 B. Front 80 Faceting 94 Best Proportions of a…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 10 of Diamond design,
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 11 of Diamond design, DIAMOND DESIGN INTRODUCTION This book is written principally for students of precious stones and jewellers, and more particularly for diamond manufacturers and diamond cutters and polishers. The author will follow the evolution…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 12 of Diamond design, 6 DIAMOND DESIGN nowhere] can one find any mathematical work determining the best shape for that gem. The present volume s chief aim is the calculation of that shape. The calculations have…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 13 of Diamond design, INTRODUCTION 7 precious stones, although it will be found advisable in the case of stones of an agree- able colour to cut the gem somewhat thicker than the calculations warrant, so as…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 14 of Diamond design, Part I HISTORICAL It is to Indian manuscripts and early Indian literature we turn when we want to find the origin of diamond cutting, for India has always been regarded as the…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 15 of Diamond design, HISTORICAL 9 of the diamond as a gem or as a crystal- with exceptional qualities does not go back in India to the unfathomable antiquity fo which books on diamonds generally refer.…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 16 of Diamond design, 10 DIAMOND DESIGN refractive and brilliant. In the Milinda- panha (Questions of King Milinda) (about first century B.C.) we read that the diamond ought to be pure throughout, and that it is…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 17 of Diamond design, HISTORICAL II tioned. It is, however, likely that, where the pohshing of other precious stones was accomplished in that manner, that of diamonds themselves cannot have been entirel}^ unknown. What pohshing there…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 18 of Diamond design, 12 DIAMOND DESIGN there were also European polishers in India at that time, and that it was to them the larger stones were given for cutting. Whether they had learnt the art…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 19 of Diamond design, HISTORICAL 13 its owner, the Great Mogul Aurung Zeb, of Delhi. This kind of cut is characteristic of most of the large Tn d i a n stones, such as theOrlow(fig.2), which…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 20 of Diamond design, 14 DIAMOND DESIGN Fig. 4. Various other shapes are described, such as point stones, thick stones, table stones (fig. 5), etc. But the chief characteristic remains all these diamonds have been cut…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 21 of Diamond design, HISTORICAL 15 ing ill Nurnberg (Germany) in 1375, where they formed a guild of free artisans, to which admission was only granted after an apprenticeship of five to six years. We do…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 22 of Diamond design, i6 DIAMOND DESIGN for a very small weight, and could easily be carried in case of flight. Priests used them in the ornaments of temples or churches they have not infrequently been…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 23 of Diamond design, HISTORICAL 17 work met with success, and where the industry started developing. In or about 1476 Lodewyk (Louis) van Berquem, a Flemish polisher of Bruges, introduced absolute symmetry in the dis- position…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 24 of Diamond design, i8 DIAMOND DESIGN As has already been shown, we know now that diamonds were polished at least a century before Lodewyk van Berquem lived. And as diamond is the hardest substance known,…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 25 of Diamond design, HISTORICAL 19 What Van Berquem probably did ori- ginate is, as already stated, rigid symmetry in the design of the cut stone. The intro- duction of the shape known as pendeloque or…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 26 of Diamond design, 20 DIAMOND DESIGN the work of Van Berquem. At any rate, they are typical of the kind of cut he introduced. The pendeloque shape did not meet with any very wide success.…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 27 of Diamond design, HISTORICAL 21 pieces of rough or split diamond. Such material is even now frequently cut into roses, chiefly in the smaller sizes. Fig. 7. In the chapter upon the design of diamonds…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 28 of Diamond design, 22 DIAMOND DESIGN of the design of fig. 9. They had sixteen facets, excluding the table, on the upper side. Fig. 9, They are called double-cut brilliants. Vincent Peruzzi, a Venetian polisher,…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 29 of Diamond design, HISTORICAL 23 than in the rose. Yet diamonds of that cut, when seen nowadays, seem exceedingly dull compared to modern-cut ones. This dullness is due to their too great thickness, and to…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 30 of Diamond design, 24 DIAMOND DESIGN p. 17) diamonds were made absolutely circular in plan (fig. 37). The gradual shrinking-in of the corners of an old-cut brilliant necessitated a less thickly cut stone with a…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 31 of Diamond design, HISTORICAL 25 vivid fire in the diamond, regardless of the loss of weight. The weight of diamond removed by bruting and by polishing amounts even in the most favourable cases to 52…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 32 of Diamond design, Part II OPTICAL It is to light, the play of Ught, its reflection and its refraction, that a gem owes its brilliancy, its fire, its colour. We have therefore to study these…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 33 of Diamond design, OPTICAL 27 and if transmitted unaltered it will appear colourless. The diamonds used as gems are generally colourless or only faintly coloured it can be taken that all the light that passes…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 34 of Diamond design, 28 DIAMOND DESIGN so as to get as large an area as possible, and in that way take full advantage of the lustre. In a diamond, the amount of light re- flected…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 35 of Diamond design, OPTICAL 29 into it follows the best path possible for producing pleasing effects upon the eye, then the gem is perfectly cut. The whole art of the lapidary consists in proportion- ing…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 36 of Diamond design, 30 DIAMOND DESIGN that surface is highly polished, as in the case of mirrors, or polished metals or gems, the reflection is perfect and an image is formed. The surface may also…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 37 of Diamond design, OPTICAL ^.i Then the eye is placed in line with FO at I, so that Q is hidden by P. Without moving the eye, two more pins R and S are inserted,…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 38 of Diamond design, 32 DIAMOND DESIGN erected on AB at that point, the angles N M P and N M S will be found equal. The above experiment may be repeated along other directions, but…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 39 of Diamond design, OPTICAL 33 angle of incidence, and the angle N M S angle of reflection. The laws of reflection (verified by the above tests) can now be formulated as follows I. The angle…
- Contributor: Tolkowsky, Marcel
- Date: 1919
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Image 40 of Diamond design, 34 DIAMOND DESIGN except in the particular case when the pencil is perfectly vertical. We can study the laws of refraction in a manner somewhat similar to that adopted for the reflection…
- Contributor: Tolkowsky, Marcel
- Date: 1919