XVI TABLE OF CONTENTS. 



Page. 



,61. Direction of Cleavage constant, , 69 



. 62. Form of Cleavage, 69 



. 63. But one Form of Cleavage (generally) in the members of a 



species, 72 



. 64. Relation between Forms of Cleavage and Crystals, . . 72 



. 65. Relation between Forms of Cleavage and Primary Forms, 75 

 . 66. Primary Form, in the Absence of Cleavage, how established, 75 



. 67. Directions for ascertaining the Primary Forms of Crystals, 76 



. 68. Fracture, 79 



. 69. Kinds of Fracture, 79 



. 70. Surface, 80 



SECTION II. 

 Compound Minerals. 



.71. Regular and Irregular Composition, .... 82 



.72. Regular Composition of two Individuals, .... 83 



. 73. Regular Composition of more than two Individuals, . . 89 



. 74. Irregular Composition. Groupe and Geode of Crystals, 90 



. 75. Imitative Shapes, 90 



. 76. Imitative Shapes originating in the Groupes of Crystals, 91 



. 77. Imitative Shapes arising out of the Geodes of Crystals, 91 



. 78. Amorphous Composition, 93 



. 79. Accidental Imitative Shapes, ...... 94 



. 80. Regular Accidental Imitative Shapes. Pseudomorphoses, 94 



.81. Irregular Accidental Imitative Shapes, .... 97 



.82. Particles of Composition, 98 



. 83. Single and Multiple Composition, 100 



. 84. Characteristic Marks of Composition, .... 100 



. 85. Structure of Compound Minerals, 102 



