VI CONTENTS 



XVIII. Novaculite quarries, Arkansas 19G 



XIX. Chert quarries of the Great Plains 201 



Oklahoma 201 



Kansas 209 



XX. Quartzite quarries, Wyoming 210 



XXI. Obsidian mines 214 



XXII. Steatite quarries 228 



XXIII. Mica mines 241 



XXIV. The red pipestone quarry 253 



XXV. Hematite ore and paint mine, Missouri 2G6 



XXVI. Tunjuoise mines 271 



XXVII. Quarries of building stone 274 



XXVIII The stone-shaping arts 278 



XXIX. Fracture processes 283 



Percussion fracture processes 283 



XXX. Pressure fracture jtrocesses 304 



XXXI. Crumbling processes 330 



XXXII. Abrading processes 344 



XXXIII. Incising processes 358 



XXXIV. Piercing processes 363 



XXXV. Fire fracture processes 364 



XXXVI. Cushing's account of shaping processes 366 



Bibliography 368 



Index 373 



