CONTENTS

y
xh

CHAPTER IX

ORES oF Iron 7 . :
Iron—History and Qualities. Ore Supplies. Classification of
Iron-ores. Igneous Ores—Titaniferous Magnetites, Contact
 Ores. Primary Lodes—Czecho-Slovakia and Westphalia.
 Replacement Ores—Pyritic Masses, Oxide Ores. Bodies
due to Descending Solutions—Cumberland, Bilbao, Lake
Superior, Gellivaara, Adirondacks, and Mid Sweden. Ancient
Surface Sheets—Kiruna, Bedded Ironstones. Aqueous Precipitates.
 Blackband Ores. Bog Iron Ores. Surface Ores
—Efflorescent, Residual, and Alluvial Ores,

PAGE
129

CHAPTER X

Ores or MANGANESE AND CHROMIUM
Manganese Ores.
Chromium

CHAPTER XI

ORES oF ALUMINIUM, INCLUDING Bauxite
Aluminium—TUses and Separation. Bauxite.

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PART III

EARTHY MINERALS
CHAPTER XII

THE Micas, ASBESTOS, AND GEMS . . . ’ , . 15%
The Micas—Distribution and Uses. Pneumatolytic Origin.
Mining Economics.
Asbestos. Monazite. The Gems—Diamond, South Africa,
Brazil; theories of formation based on supposed artificial
diamonds. Corundum group. Miscellaneous gems—Topaz,
Zircon, Jade, Lapis Lazuli, Garnets, Olivine, Opal.
CHAPTER XIII

Cray . . . 168
Essential Properties of Clay. China Clay—Pneumatolytic Origin,
German Deposits of various modes of formation. Fuller's
Earth.
CHAPTER XIV

BUILDING STONES AND ROAD METALS . 3 * . 175
Building Stones. Causes of Decay. Tests of Building Stones.
Microscopic Examination—Panama * Breaks.” Varieties of
Building Stones. Stone Preservation, Road Metals