CONTENTS 
y 
xh 
CHAPTER IX 
ORES oF Iron 7 . : 
Iron—History and Qualities. Ore Supplies. Classification of 
Iron-ores. Igneous Ores—Titaniferous Magnetites, Con- 
tact Ores. Primary Lodes—Czecho-Slovakia and Westpha- 
lia. 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 Pre- 
cipitates. 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. 
, 2 
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