I9I3] ROGERS— THE NOMENCLATURE OF MINERALS. 611 



mixture of magnesium and iron orthosilicates but the names hyalo- 

 siderite and hortonolite in the oHvine group are hardly necessary. 

 Epidote is an isomorphous mixture of basic calcium aluminum 

 orthosilicate, clinozoisite, and basic calcium iron orthosilicate, not 

 yet found. Hypersthene is an isomorphous mixture of magnesium 

 metasilicate, enstatite, and ferrous metasilicate, not yet found. It 

 might be well as assign arbitrary limits to olivine, hypersthene, and 

 epidote. This must be done if the names are to be accurate. Dana 

 uses the name hypersthene for orthorhombic pyroxene with ferrous 

 oxid content of over ten per cent. For these various isomorphous 

 mixtures arbitrary divisions similar to those used in the quantitative 

 classification of igneous rocks might be used. 



Are the names of mineral species to be arbitrary or can any 

 system of giving names be used ? Leaving out the binomial nomen- 

 clature there are three possibilities to consider. 



1. Chemical Names. — As minerals are substances of definite 

 chemical composition purely chemical names will appeal to some as 

 being the simplest and best. But minerals are often complex in 

 composition and the chemical names would be long and cumbersome. 

 While accurate they are not convenient. Moreover the name of a 

 mineral connotes certain physical properties. Calcite is more than 

 calcium carbonate. It is calcium carbonate with certain definite 

 physical properties. The chemist would obviate this difficulty by 

 using the term a-CaCOg for calcite and /J-CaCOs for aragonite. 

 Except for the elements, perhaps, distinctive names are preferable 

 to chemical names. 



2. Arbitrary Names. — The names used at present are derived 

 from the locality at which the mineral was first found, from the 

 name of the person who discovered or described the mineral, or 

 they are based upon some prominent physical or chemical char- 

 acteristic. They are arbitrary and without system except that 

 most of them end in -ite (from the Greek and Latin -itis or -ites, 

 which was added to a word signifying a quality, use, or locality of 

 the mineral). Among other terminations are -ane, -ine, -ase, -ote, 

 -ole, and -ome while older names include galena, quartz, garnet, etc. 

 Some of the names have a chemical significance but even thev are 



