Washington — Suggestion for Mineral Nomenclature. 139 



tively, as cases in point. Whether there is any essential dif- 

 ference between physical and chemical isomerism may perhaps 

 be doubted, but further discussion of this topic is uncalled for 

 here. 



In spite of this advanced state of the classification of min- 

 eralogy, the nomenclature is in much the same condition as in 

 the time of Pliny, when minerals were named after their qual- 

 ities, localities, or uses, with the systematic termination -ites 

 or -itis (modern -ite), the only innovations being the intro- 

 duction of names after persons and certain other arbitrary ter- 

 minations. Despite attempts to introduce binomial names, 

 analogous to those of botany aud zoology, or those based on 

 chemical characters, systematic mineralogy has adhered closely 

 to the nomenclature of the first century A. D.* 



As a consequence, mineral nomenclature, like that of the older 

 rock classifications, is unable to express the facts of classification. 

 Roots derived from names of places or persons can convey in 

 themselves absolutely no idea of the mineralogical characters, 

 and even those derived from chemical or physical characters 

 are applicable to many different minerals. Thus cuprite 

 applies equally well to CuO as Cu 2 0, and octahedrite would be 

 an appropriate name for magnetite, franklinite, or fluorite. 

 All such name roots are purely arbitrary in their mnemonic 

 connotations, but at the same time, by long association, a laige 

 proportion of mineral name roots convey very definite ideas of 

 the mineral and chemical characters. 



Again, with the uniform and monotonous general use of a 

 single termination (-ite), and the arbitrary and unsystematic 

 employment of others, the characters and relations of minerals, 

 and even of mineral groups, are concealed. No distinction is 

 evident from the name between a rare or uncharacteristic vari- 

 etal form of a certain mineral (as hiddenite or sagenite), and 

 a large mineral group which may include many distinct min- 

 erals (as zeolite or chlorite). In the case of a few of the com- 

 monest and largest groups of related minerals we have names, 

 fortunately distinctive because of their terminations, which 

 may be applied to the group as a whole, as spinel, feldspar, 

 garnet, pyroxene, amphibole, mica ; and the general usefulness 

 and common application of these is sufficient evidence of the 

 value of such group names. In other cases the difficulty of 

 expressing relationships is got round and the need supplied by 

 the word "group" after the name of a typical representative : 

 as the pyrite, calcite, aragonite, olivine, and apatite groups. 

 In all these group names the underlying idea which connects 

 the members is adherence to a certain type of chemical formula, 

 with isomorphous replacement, and, of equal importance, close 



* Of. Dana, System Mineralogy, 1892, p. xl. 



