99 DESCRIPLFIONS OF MINERALS. 
2. Boron Group.—The chief oxide a trioxide, its formula 
R,O;. Includes compounds of Boron with oxygen. 
3. Arsenic Group.—The chief oxide a pentoxide, its formula 
Rk, O;. Includes Arsenic and arsenic sulphides and oxides; An- 
timony and antimony sulphide, arsenide and oxides; Bismuth 
and bismuth sulphide, telluride and oxide. 
4, Carbon Group.—The chief oxide a dioxide, its formula 
RO,. Includes Carbon (Diamond, Graphite) and carbon diox- 
ide. (Quartz, $i O,, belongs here chemically, but is placed with 
the Silicates. ) 
II. Basic Division. 
Gold ; Silver; Platinum and Ividium; Palladium; Quick- 
silver ; Copper ; Lead ; Zinc; Cadmium ; Tin; Titanium ; Co- 
balt and Nickel; Uranium; Iron; Manganese; Aluminium ; 
Cerium, Yttrium, Lanthanum, Didymium and Erbium; Mag- 
nesium; Calcium; Barium and Strontium; Potassium and 
Sodium; Ammonium ; Hydrogen. 
IIT. StmicaA AND SILICATES. 
1. Silica. 
2. Anbydrous Silicates. 
1. Bisilicates. 
2. Unisilicates. 
3. Subsilicates. 
3. Hydrous Silicates. 
1. General section of Hydrous Silicates. 
2. Zeolite section. 
3. Margarophyllite section. 
IV. HyprocarBon COMPOUNDS. 
1. Oils, Resins, Wax. 
2. Asphaltum, Coals. 
GENERAL REMARKS ON ORES. 
An ore, in the mineralogical sense of the word, is a mineral 
compound in which a metal isa prominent constituent. In the 
