CHAPTER XXXIX.. Precious Stones.

PRECIOUS STONES.

Diamonds—Diamond Cutting—Rose Diamonds—Brilliants—The Diamond District in Brazil—Diamond Lavras—The great Russian Diamond—The Regent—The Koh-i-Noor—Its History— The Star of the South—Diamonds used for Industrial Purposes—The Oriental Ruby and Sapphire—The Spinel—The Chrysoberyl—The Emerald—The Beryl—The Zircon—The Topaz— The Oriental Turquoise—The Garnet—Lapis Lazuli—The Noble Opal—Inferior Precious Stones—The Agate-Cutters of Oberstein—Rock Crystal—The Rock-crystal Grotto of the Galenstock 477

LIST OF ILLUSTRATIONS.

MAPS.

Of the World, showing the distribution of Volcanoes and the Districts visited by Earthquakes to face page 60

Of Great Britain, showing the Coal-fields and chief Mining Districts 400

Of America, showing the Coal-fields and Mineral Districts 410

WOODCUTS.

PAGE

Carboniferous Forest engraved by G. Pearson, to face title

Tabular Geological Profile of Strata with corresponding engraved by G. Pearson Fossils 3

Aqueous Strata disturbed by Igneous Formations ” ” 4

Ammonites Henleyi (Middle from Haughton’s ‘Manual of Lias) Geology’ 9

Trilobite from Kemp’s ‘Phasis of Matter’ 11

Magnified Eye of Trilobite ” ” 11

Pterygotus acuminatus from Haughton’s ‘Manual of (Eurypterid) Geology’ 12

Spirifer princeps (Brachiopod) ” ” 12

Pterichthys Milleri, restored (Old Red Sandstone of Scotland) ” ” 14

Ventriculites, Fossil Sponge (Chalk) ” ” 16

Siphonia costata, Fossil Sponge, (Green Sand, ” ” Warminster) 16

Encrinus liliiformis (Muschelkalk, Germany) ” ” 17

Pentacrinus briareus ” ” 17

Marsupites ornatus (Chalk) ” ” 18

Turrilites tuberculatum ” ” 19

Restored Belemnite ” ” 19

Ichthyosaurus communis ” ” 20

Plesiosaurus dolichodeirus (British Museum—found in the from Haughton’s ‘Manual of Lias of Street, near Geology’ Glastonbury) 21

Glyptodon clavipes ” ” 25

Diagram illustrating action of engraved by G. Pearson Syphon 44

Section of an Intermittent Spring ” ” 45

Geysirs of Iceland ” ” 46

Porous Strata, Artesian Well sunk in the London Basin ” ” 49

Middle and Valley Lake Craters, from Wood’s ‘Australia’ to face Mount Gambier, South page Australia 53

Extinct Crater of Haleakala from Webb’s ‘Celestial Objects’ 57

Eruption of Vesuvius, Bay of engraved by G. Pearson, to face Naples page 81

Mud Volcanoes of Trinidad engraved by G. Pearson 94

Great Earthquake at Lisbon engraved by G. Pearson, to face page 114

Axmouth Landslip engraved by G. Pearson 128

Stalactital Cavern at Aggtelek: engraved by G. Pearson, to face the Cave of Borodla page 133

Entrance to the Cave of engraved by G. Pearson Adelsberg 137

Stalactital Cavern in Australia from Wood’s ‘Australia’ 141

Cave under Bonifacio from Forester’s ‘Corsica’ 145

Leptodirus Höchenwartii engraved by G. Pearson 163

The Proteus anguinus ” ” 165

Blind Fish (Amblyopsis spelæus) ” ” 168

Indian Rock-cut Temple engraved by G. Pearson, to face page 178

Rock Temples of Ajunta (general engraved by G. Pearson view) 182

Lower Glacière of St. Livres from Browne’s ‘Ice Caves’ 193

Ice Streams in the Upper Glacière of St. Livres ” ” 196

Entrance to the Glacière of St. Georges ” ” 201

Gallery with Tombs from Northcote and Brownlow’s ‘Roma Sotterranea’ 206

Cave in Dream Lead Mine, near engraved by G. Pearson Wirksworth, Derbyshire 216

Boring Machine in the Tunnel, taken from the ‘Illustrated Mont Cenis { } London News’ by permission 238

Boring Machine in the Second Working Gallery, Mont Cenis Tunnel ” ” 239

Process of Boring engraved by G. Pearson 251

Section of a Lead Mine in from Ure’s ‘Dictionary of Cardiganshire { Arts, } Manufacture, and Mines’. 252

Part of a Colliery laid out in four panels ” ” 255

General View of Mining engraved by G. Pearson Operations 257

Tools used by Miners in from Ure’s ‘Dictionary of Cornwall { Arts, } Manufactures, and Mines’ 258

Conveyance of Minerals engraved by G. Pearson underground 262

Miners descending Shaft in Owen’s Safety Cage ” ” 265

Timbering of a Mine from Ure’s ‘Dictionary of { Arts, } Manufactures, and Mines’ 258

Transverse Sections of Walled Drain Galleries ” ” 269

Drainage of a Mine by Adit Levels ” ” 269

Safety Lamp ” ” 280

Gold-washing in Australia engraved by G. Pearson 292

Stamping Mill from Ure’s ‘Dictionary of Arts, Manufactures, and Mines’ 306

Grinding Mill ” ” 307

The Botallack Mine, Cornwall engraved by G. Pearson 317

St. Michael’s Mount, Cornwall ” ” 333

Blast Furnace from Ure’s ‘Dictionary of Arts, Manufactures, and Mines’ 352

Pecopteris adiantoides from Haughton’s ‘Manual of Geology’ 391

Sphenopteris affinis ” ” 391

Lepidodendron elegans ” ” 392

Asterophyllites comosa ” ” 392

Sigillaria oculata ” ” 392

Calamites nodosus ” ” 393

Coalbeds rendered available by from ‘Our Coal and Our Coal Pits’ elevation, 397

Section of Coal-field south of { from Ure’s ‘Dictionary of } Malmesbury Arts, Manufactures, and Mines’ 398

Coal-basin of Clackmannanshire ” ” 403

Dudley Coal-field from Howitt’s ‘Visits to Remarkable Places’ 407

Shipping Coal ” ” 412

Coal Hewers at Work engraved by G. Pearson 415

Pitch Lake of Trinidad engraved by G. Pearson, to face page 429

Insects and Vegetable engraved by G. Pearson Substances inclosed in Amber, 452

Penrhyn Slate Quarry, North engraved by G. Pearson, to face Wales page 469

The following is a list of the full-page illustrations, included in the foregoing list, all of which, except No. 2, are engraved by G. Pearson:—

1. Carboniferous Forest to face title

2. Middle and Valley Lake Craters, Mount Gambier, South Australia to face page 53

3. Eruption of Vesuvius, Bay of Naples ” 81

4. Great Earthquake at Lisbon ” 114

5. Stalactital Cavern at Aggtelek; the Cave of Borodla ” 133

6. Indian Rock-cut Temple: Porch of the Chaitya Cave Temple, Ajunta ” 178

7. Pitch Lake of Trinidad ” 429

8. Penrhyn Slate Quarry, North Wales ” 469