LIST OF PLATES
Reading edition
PAGE
I. Gem-Stones (in colour) Frontispiece
II. Refractive Index Diagram 36
III. Interference Figures 48
IV. Jewellery Designs 62
V. Jewellery Designs 88
VI. Appliances used for Polishing Diamonds 102
VII. Polishing Diamonds 103
VIII. Slitting and Polishing Coloured Stones 104
IX. Faceting Machine 105
X. Lapidary’s Workshop and Office in England 106
XI. Lapidary’s Workshop in Russia 107
XII. French Family Cutting Stones 108
XIII. Indian Lapidary 109
XIV. Blowpipe used for the Manufacture of Rubies and Sapphires 118
XV. Kimberley Mine, 1871 140
XVI. Kimberley Mine, 1872 141
XVII. Kimberley Mine, 1874 142
XVIII. Kimberley Mine, 1881 143
XIX. Kimberley Mine at the Present Day 144
XX. Wesselton (open) Mine 145
XXI. Loading the Blue Ground on the Floors, and Ploughing it over 146
XXII. Washing-Machines for Concentrating the Blue Ground 147
XXIII. Diamond-Sorting Machines 148
XXIV. Kafirs Picking out Diamonds 149
XXV. Cullinan Diamond (natural size) 168
XXVI. Large Aquamarine Crystal (one-sixth natural size), Found at Marambaya, Minas Geraes, Brazil 196
XXVII. Gem-Stones (in colour) 226
XXVIII. Opal Mines, White Cliffs, New South Wales 252
XXIX. Gem-Stones (in colour) 256
XXX. Natives Drilling Pearls 294
XXXI. Metal Figures of Buddha Inserted in a Pearl-Oyster 296
XXXII. Sections of Culture Pearl 297
GEM-STONES