Hardness 10: Table of contents

Introduction

  • The Genesis of diamond 9
  • The earth’s core still largely unknown 10
  • A terrifying force 11
  • Craftsmanship 13

Chapter I

  • History and legends 15
  • Lode Van Berckem and the origin of the diamond cutting technique 17
  • “Naif” diamonds 17
  • Testimony of Robert De Berquem 19
  • Conclusion 22
  • Legends and stories 23
  • History of Diamond Cutting 26
  • Automatic cutting 32
  • The value of diamond 34

Chapter II

  • Famous Stones 39
  • The most famous stones 39

Chapter III

    Characteristics of diamond 81
  • 1. Structure 81
  • 2. Crystalline morphology 82
  • 2.1. General features 82
  • I) Fundamental growth morphologies 87
  • 1. Octahedral growth 87
  • 2. Fibrous growth 88
  • 3. Cuboid growth 89
  • 4. Additional growth morphologies observed in synthetic diamonds only 91
  • II) Combination of several growth morphologies in one single crystal 99
  • Regular, multiple alternation of octahedral and cuboid growth sectors. 99
  • Simultaneous octahedral and cuboid growth: “Asteriated” and “reentrant” diamonds. 100
  • Octahedral then fibrous: Coated diamonds 101
  • III) Other growth events that modify morphology 102
  • 1) Twins 102
  • 2) Parallel growth 104
  • 3) Random intergrowth 104
  • IV) Post growth evolution that modify morphology 105
  • 1) Dissolution 105
  • 2) Breaks and cleavages 108
  • V. Polycrystalline diamonds 109
  • 2.2. Crystalline forms of diamond 110
  • 2.2.1. General forms 110
  • 2.2.2. Maccles or twinned crystals 114
  • 2.2.3. Other forms 115
  • 3. Mechanical properties 116
  • 3.1. Density 116
  • 3.2. Hardness 117
  • 4. Chemical properties 125
  • 5. Optical properties 126
  • 5.1. Refraction of light 126
  • 5.2. Reflective capacity 127
  • 5.3. Dispersion 128
  • 5.4. Birefringence 128
  • 5.5. Fluorescence 129
  • 5.5.1. Colour and fluorescence in diamond 130
  • 5.5.2. Influence of fluorescence on the colour of diamonds 131
  • 5.5.3. Conclusion 136
  • 5.6. Phosphorescence 137
  • 5.7. Transparency to X-rays 137
  • 6. Thermal properties 138
  • 7. Electrical properties 141
  • 8. Surface properties 144
  • 9. Other properties 145
  • 10. Transparency 145
  • 11. Colour and colour treatment 145
  • 12. Inclusions 164
  • 12.1. Feathers or gletsen 165
  • 12.2. Liquid or gas inclusions 166
  • 12.3. Solid inclusions 166
  • 12.4. Inclusions in South African diamonds 169
  • 12.4.1. Spinel inclusion (chromite in a cleaved lamella) 169
  • 12.4.2. Peridote inclusion (forsterite) in a polished diamond 169
  • 12.4.3. Diopside inclusion (pyroxene) in a polished diamond 170
  • 12.4.4. Haematite inclusion in a rough diamond 171
  • 12.4.5. Graphite inclusion in a rough diamond 171
  • 12.4.6. Garnet inclusion (pyrope) in a cleaved lamella 171
  • 12.5. Treatment of inclusions 173
  • 13. Diamond imitations 204
  • 14. Synthetic diamond 214
  • CVD Chemical Vapour Deposition 224
  • Detection 226
  • 15. Improvement of colours in an artificial way (detection) 229
  • 16. Naturally or artificially coloured diamonds 232
  • Colouration after irradiation 235
  • Hpht (high pressure and high temperature) treatment of gem quality diamonds 235
  • Where are we ? 236
  • CVD (Chemical Vapor Deposition) synthesis 262
  • Photoluminescence 280
  • Cathodoluminescence 281
  • Lonsdaleite 282
  • The carbon revolution 283
  • The nanotubes : infinite applications 284
  • Carbone 60 : harder than natural diamond 285
  • Non cvd diamond film 289
  • The eliminated friction by carbon 290
  • Journey to the centre of the earth 293
  • Chameleon diamonds 294
  • Physician’s contributions to diamond 297
  • Diamond in the service of geology : the diamond anvil 297

Chapter IV

  • Geology, prospecting, mining 305
  • 1. Geology 305
  • 1.1. Formation of the Earth’s mantle 305
  • 1.2. Origin in meteorites 307
  • 2. Deposits 310
  • 3. Prospecting 313
  • 3.1. Systematic prospecting of large surfaces 313
  • 3.2. Hydrographical prospecting 315
  • 3.2.1 Traditional alluvial prospecting 315
  • 3.2.2. Alluvial prospecting in a dense environment 317
  • 3.2.3. Exploitation — mining 318
  • The “sniffing” airplane and diamonds 318
  • 4. Exploitation and extraction 320
  • 4.1. Primary deposits 320
  • 4.1.1. Open cast mining 320
  • 4.1.2. Underground mining 324
  • 4.2. Secondary eluvial and alluvial deposits 325
  • 4.3. Coastal and marine deposits 326
  • 5. Ore treatment and diamond recuperation 328
  • 6. Sorting of rough diamonds 335
  • 6.1. Gem diamond 338
  • 6.2. Industrial diamond 343
  • The polycrystalline diamond 343
  • The De Beers monocrystal 344
  • Advanced diamond composite 345
  • Classification of industrial diamonds 349
  • Application fields for diamond tools 350
  • The binding 377
  • Synthetic diamond films for industry 378
  • Synthetic diamond and the industry 380
  • 6.3. Crushing boart or bort383
  • The continental drift and diamond 384
  • Evaluation of a batch of rough diamond 387
  • Twins – makeables – impossible to saw 387
  • Colour classification 389
  • 1. The colourless 390
  • 2. The tinted 391
  • 3. The coloured 391
  • The yellow 391
  • The brown stones 391
  • The fancy colours 392
  • The chromascope colorimeter 392
  • The form 394
  • The weight 394
  • Sorting according to characteristics 395
  • The closed 397
  • The spotted 398
  • The irregulars398
  • The naats 398
  • Bort or boart 399
  • Industrial diamond 399
  • Near gems 399
  • The scales 399
  • The risks of buying rough upstream 401
  • The imitations and manipulations of rough diamond 403
  • There are two methods of evaluation 404
  • Practically speaking 409
  • The pioneering factor : “T estimation” 413
  • Advice for buying rough outside the producers 414
  • Diamonds in Morocco ? 414
  • The diamond sites and geofractals 416
  • JORC-code = joint committee of ore reserves calculations 423
  • The discovery of the most ancient diamonds of our planet 425
  • Kimberlite, the “mother rock” or “elevator”-lift transporter of diamond 426
  • The different sites of the kimberlite 429
  • Chemical composition 430
  • Lamproite or kimberlite 431
  • What is kimberlite ? 431
  • Satellite ores 434
  • A diamond in the galaxy 434

Chapter V

  • Main producing countries 439
  • Africa 440
  • South Africa 440
  • Angola 448
  • Zimbabwe 452
  • Liberia 453
  • Sierra Leone 454
  • Tanzania (former Tanganyika) 459
  • Democratic Republic of the Congo460
  • Namibia 468
  • Central African Republic 470
  • Ghana 471
  • Ivory Coast 472
  • Guinea 473
  • Botswana 476
  • Lesotho 484
  • Cameroun 485
  • Mauritania 485
  • Swaziland 486
  • America 486
  • Brazil 486
  • Canada 491
  • United States of America 498
  • Venezuela 499
  • Guyana 500
  • English Guyana 501
  • Asia 502
  • Borneo — Indonesia — Kalimantan 502
  • China 503
  • Burma-Myanmar 509
  • India 509
  • Russia 514
  • Australia 527
  • Europe 529
  • Finland 529
  • Sweden 530
  • Norway 530
  • Greenland 530
  • Rio Tinto and diamonds534
  • Dominion Diamond Corporation 539

Chapter VI

    Cleaving 545
  • 1. Basic principles 545
  • 2. The cleaver’s tools 546
  • 3. Operation 550
  • 3.1. Preparatory work before cleaving 550
  • 3.2. Kerfing and cleaving 553
  • 3.3. Cleaning 555
  • 4. Cleaving in practice 555
  • 5. Cleaving productivity 557

Chapter VII

  • Sawing 563
  • 1. Principe 563
  • 2. Equipment of the sawyer 566
  • 2.1. The Sawing Bench 567
  • 2.2. Driving Power 567
  • 2.3. The Sawing Machine 570
  • 2.3.1. Description 570
  • 2.3.2. The sawyer’s tools 573
  • 2.4. Automatic sawing and laser sawing 576
  • 3. Procedure 579
  • 3.1. Marking or designing 579
  • 3.2. Verstellen or Setting 581
  • 3.3. Mounting of the stone on the sawing machine 584
  • 3.4. Sawing 587
  • 3.5. Cleaning 591
  • 4. Sawing in practice 593
  • Sawing naats 597
  • 5. Production and productiveness 600
  • 6. Laser cutting 603
  • 6.1 Laser sawing 603
  • Partial use of laser 604
  • 6.2. Sawing loss 606
  • 6.2.1. Definition 608
  • 6.2.2. Examples 609
  • 6.2.3. Comparing mechanical and laser sawing 609
  • 6.3. Software used 612

Chapter VIII

  • Bruting 619
  • 1. Basic principles 619
  • 2. Equipment 622
  • 2.1. The Bruting Machine 624
  • 2.1.1. Installation 624
  • 2.1.2. Description 625
  • 2.2. The bruting sticks 634
  • 2.3. Bruting dops 635
  • 2.4. Other accessories 637
  • A. Setting pins 637
  • B. The hammer 638
  • C. The loupe and the gauge 638
  • 3. Working method 639
  • 4. Bruting in practice 641
  • 5. Production and productivity 646
  • 5.1. The portable bruting machine of the WTOCD 647
  • 5.2. Universal Cone Generator (automatic bruting machine) 649
  • Superbruter of the WTOCD 652
  • EOS bruting machine 655
  • 6. Research on bruting 661

Chapter IX

  • Polishing 667
  • 1. Principles and historic survey 667
  • Polishing directions according to hardness 674
  • 2. Polishing equipment 677
  • 2.1. The polishing mill 677
  • 2.2. The polishing scaife 680
  • 2.3. The polishing tang 683
  • 2.4. The dop or polishing dop 687
  • 2.5. The sleigh 696
  • 2.6 Automatic polishing 698
  • The GS 3000 701
  • 2.7. The computer and diamond polishing 704
  • 3. Working method 709
  • 3.1 Sorting before polishing 709
  • 3.2. Positions of the tang 710
  • 3.3. Levelling of a tang with adjustable legs 711
  • 3.4. Practical hints 713
  • 3.5. Boiling and sorting 714
  • 3.6. Production and productivity 715
  • 4. Polishing in practice 716
  • 4.1. polishing of the table 717
  • 4.2. Cross work 720
  • 4.3. Polishing of the bottom side of a four point 726
  • 4.3.1 Cross work 726
  • 4.4. Polishing of the top side of a four point 728
  • 4.4.1. Cross work 728
  • 4.4.2 8/8 cut or setting in 8 730
  • 4.4.3.Polishing of the bottom side of a four point 731
  • 4.5. Polishing of eight cuts or single cuts 732
  • 4.6. Cross working of “whole” or makeables 733
  • 4.7. Polishing of bottom corners 734
  • 4.8. Polishing of top corners 735
  • 4.9 Eight cut of “whole” or makeables 736
  • 5. Brillianteering 738
  • 5.1 Stars 739
  • 5.2. Top Halves 739
  • 5.3. Bottom Halves 741
  • 5.4 Verstel 741
  • 6. Different polishing grains of certain diamond crystals 742
  • 6.1. The polishing grains 742
  • 6.2. Polishing grains of four points 743
  • 6.2.1. Cross work 743
  • 6.2.2. Eight-cut polishing 743
  • 6.3. Eight-cut polishing of the bottom 744
  • 6.3.1. Pavilions 744
  • 6.3.2. Position, number, shape 744
  • 6.3.3. Requirements when polishing 744
  • 6.3.4. Mistakes to be avoided 744
  • 6.3.5. Polishing directions and “starting” a facet 744
  • 6.3.6. Polishing procedures 745
  • 6.4. Polishing of pavilions with an imperfect or polished culet 746
  • 6.4.1. Natural culet 746
  • 6.4.2. Long culet 746
  • 6.4.3. Polished culet 747
  • 6.5. Brillianteering 747
  • 6.5.1. Stars 747
  • 6.5.2. Top halves 748
  • 6.5.3. Bottom halves 749
  • 6.6. Viewing of stones with a loupe751
  • 6.6.1. Whole stones or makeables751
  • 6.6.2. Remark 752
  • 6.7. Lamellar structure etchings growth marks 752
  • 7. Production and rentability 752
  • 7. Derived forms 753
  • 7.1. The three point 753
  • 7.1.1. General features 753
  • 7.1.2. Polishing grains which can be tried out 755
  • 7.2. The two point 760
  • 7.2.1. General features 760
  • 7.2.2.Polishing grains 761
  • 7.3 The brilliant geometry 765
  • 7.3.1. A brilliant from a straight pyramid 765
  • 7.3.2. A brilliant from a regular octahedron 767
  • 7.3.3. Conclusion 769
  • Hearts & arrows 769
  • 8. Fancy cuts 773
  • 9. The marquise cut 774
  • 9.1. Cross work 778
  • 9.1.1. Top 779
  • 9.1.2. Bottom 779
  • 9.2. Brillianteering 780
  • 9.2.1. Points 780
  • 9.2.2. Stars 781
  • 9.2.3. Top halves 781
  • 9.2.4. Bottom halves 781
  • 10. The pendeloque or pear cut 782
  • 10.1. Cross work 784
  • 10.1.1. Top 784
  • 10.1.2. Bottom 785
  • 10.2. Brillianteering 785
  • 10.2.1. Bezels 785
  • 10.2.2. Stars 786
  • 10.2.3. Top halves 786
  • 10.2.4. Pavilions 786
  • 10.2.5. Bottom halves 787
  • 11. The oval cut 787
  • 11.1. Cross work 788
  • 11.2. Brillianteering 788
  • 12. The heart cut 788
  • 13. The baguette cut 790
  • 13.1 Side view 791
  • 13.2. Top 791
  • 13.3. Bottom 791
  • 14. The emerald cut 792
  • 14.1 Side view 792
  • 14.2. Top 793
  • 14.3. Bottom 793
  • 15. The triangle cut 794
  • 15.1. The normal triangle 794
  • 15.2. The brillianteered triangle 795
  • 15.3. Cross work 795
  • 15.4. Brillianteering 795
  • 16. The rose cut 795
  • 17. The swiss cut 797
  • 18. The carre or square cut 798
  • 19. The radiant cut 798
  • 20. The flanders brilliant 798
  • New fancy cuts 801
  • 21. Diamond sculptures 828
  • 24. Maintenance of polishing equipment 832
  • 25. Scientific research and technological innovations related to the cutting of gem diamonds 837
  • 25.1. The price of a diamond 838
  • 25.2. Hardness 838
  • 25.3. Thermal conductivity 839
  • 25.4. Refractive index 839
  • 25.5. Concrete cases of research and innovation 840
  • Systematic research by specialised research centres 841
  • a) The bruting project 841
  • b) The polishing project 845
  • c) Consulting 846
  • d) Conclusion 847
  • 25.6. Diamond dust suction installations 848
  • 26. Description and use of automatic machines (WDT) 849
  • 26.1. Preliminary remarks 849
  • 26.2. New generation 850
  • 26.2.1. Installation 850
  • 26.2.2. Brief description of the major accessories 852
  • 26.2.3. The installation of the polishing machines 852
  • 26.2.4. Organisation flow chart 853
  • 26.2.5. Layout of an automatic polishing factory 853
  • 26.3. The mark III 853
  • 26.3.1. The machine and the different parts 853
  • 26.3.2. Operation 855
  • 26.3.3. Blocking 856
  • 26.3.4. Brillianteering of the top 857
  • 26.3.5. Brillianteering of the bottom 859
  • 26.4. The GS 3000 861
  • 26.4.1. Short description of the automatic grain seeker 861
  • 26.4.2. The control panel 863
  • 26.4.3. The machine 863
  • 26.4.4. The polishing procedures 863
  • 26.5. The VR2 863
  • 26.6. Octopus 864
  • Circumstances of use 866
  • Start up, operate and switching off the machine 870
  • 26.7. Woscam 895
  • 27. Feathers and cleavages during polishing 897
  • 27.1. Foreign elements as inclusions 897
  • 27.2. Different kinds of inclusions 897
  • 27.2.2. Cleavages in the polishing direction 898
  • 27.2.3. Cleavages in non-polishing directions 898
  • 27.4. Positioning of cleavages on the wheel 899
  • 27.5. Decoloring of cleavages 899
  • 27.6. Burning of the surface of the diamond : the causes 899
  • 28. The polishing of naat stones or maccles 900
  • 28.1. Definition of naat stones or maccles 900
  • 28.2. External characteristics 900
  • 28.3. Different types 900
  • 28.3.1. Naat stones 900
  • 28.3.2. Maccles 901
  • 28.3.3. Twins 901
  • 28.3.4. Black naats 901
  • 28.3.5. Block naats 901
  • 28.3.6. Fibre naats 902
  • 28.4. Treatment techniques 902
  • 28.4.1. Polisher 902
  • 28.4.2. Method for a single naat 902
  • 29. Maintenance of polishing equipment 903
  • 30. The diamond expert computer 907
  • 30.1. Diamond dust suction installations 910
  • 30.2. Avalon – Control of the polishing’s finish 911
  • 30.3. Merlin 913
  • 30.4. Solid 914
  • 30.5 Excalibur 915
  • 31. Lexus automatic device for cross shaping made in india 916
  • 32. Into the heart of diamond 916

Chapter X

  • Equipment for the diamond dealer 921

Chapter XI

  • Diamond Trade 947
  • 1. Historic evolution of the diamond trade 947
  • 2. De Beers 956
  • De beers at the 21st century 979
  • Added value along the diamond production chain 980
  • Grandeur and decline of a diamond centre : Amsterdam 984
  • A report which hastened the fall of Amsterdam 987
  • Epilogue 988
  • Dubai, a new diamond centre 989
  • Certificate 990
  • The cutting 990
  • Jewellery 991
  • China 991
  • India 994
  • 3. The diamond market 995
  • 3.1. The market for rough diamonds 1016
  • Supplier of Choice 1017
  • Back to the roots 1018
  • Blood diamonds 1023
  • The kimberley process 1025
  • 3.1.1. De Beers and the “sights” 1028
  • 3.1.2. The market for rough diamonds outside De Beers 1029
  • 3.1.3. The diamond bourses 1036
  • 3.1.5. The seal (“cachet”) 1056
  • 3.2. The market for polished diamonds 1058
  • 3.3. Elements of evaluation (the 4 c’s) 1058
  • 4. Absorption spectroscopy 1095
  • 4.1. Universal spectrophotometer 1095
  • 4.2. Diamond photometer 1097
  • 5. Clarity 1102
  • 5.1. IDC directive for the clarity grade of internal characteristics 1109
  • 5.2. Location 1114
  • 5.3. Number 1115
  • 5.3.1. Critical characteristics — asterisk zone 1116
  • 5.4. contrast 1117
  • 5.5 Measuring technique 1120
  • 5.5.1. Size 1120
  • 5.6. Measuring instruments 1122
  • 6. Proportions and finish 1137
  • The new norms of the IDC 1137
  • 7. Emotional value 1159
  • 8. Certificates 1161
  • 9. Identification 1181
  • 9.1. X-ray topographic pictureX 1182
  • 9.2. Okuda system 1182
  • 10. The jeweller’s sales room 1208
  • The diamond high council (HRD) before and today 1222
  • London, world centre of diamond insurances 1231
  • Why participate in a fair ? 1238
  • You have decided to participate in a trade fair 1239
  • 6 months before fair 1239
  • 5 months before fair 1240
  • 3 months before fair 1244
  • 1 Month before fair 1245
  • 2 Weeks before fair 1246
  • 1 Week before fair 1246
  • 2 Days before fair 1248
  • Departure 1248
  • Arrival 1249
  • D-Day 1250
  • After closing time 1251
  • Last fair day 1252
  • Flying home 1253
  • Back at your office 1253
  • One week later 1253
  • Psychology 1254
  • Conclusion1255
  • Raffles in the profession 1255
  • Banks in the diamond sector 1270
  • The Antwerpse Diamantbank, first diamond bank ! 1270
  • The NHM 1271
  • The ABN and the AMRO 1272
  • The State Bank of India 1272
  • Bibliography 1277
  • Glossary 1283