A REVIEW OF THE AMORPHOUS MINERALS 523 



adopted when so many new names of mere varieties or mixtures 

 of older minerals 1 are apparently welcomed. 



NAMES FOR AMORPHOUS MINERALS 



If it be granted that amorphous minerals deserve recognition, 

 then names of some kind are necessary. Are these to be distinctive 

 names or modifications of the names of the corresponding crystal- 

 line minerals? Cornu used the prefix "gel" with the crystalline 

 modification (e.g., gelvariscite, for the amorphous equivalent of 

 variscite). Tucan 2 employed a similar device, except that "gel" 

 came after the root name instead of before it (e.g., hematogelite 

 for colloidal ferric oxid) . Wherry 3 proposed that the Greek letter 

 k (the abbreviation of koXKo) be used as a prefix to the crystalline 

 compound (e.g., /c-limonite for stilpnosiderite) . 



A serious objection to all these proposals lies in the fact that 

 the amorphous mineral is not related to one polymorphous modi- 

 fication any more than to another. Most mineral substances are 

 known in but one crystalline modification, but other modifications 

 may be found in the future, as polymorphism seems to be a general 

 phenomenon of nature. 



The name of any crystalline mineral connotes certain crystal 

 forms and physical properties as well as a given chemical composi- 

 tion. It is absurd, then, to speak of amorphous calcite or amor- 

 phous aragonite. The proper term to use is amorphous calcium 

 carbonate. 



Distinctive names, then, are necessary, or at least advisable, 

 for the amorphous equivalents of crystalline as well as for the other 

 amorphous minerals. As an illustration of the need of distinctive 

 names for amorphous minerals, let me cite the case of variscite. 

 Cornu, in 1909, called its amorphous equivalent gelvariscite, but 

 Schaller has recently described lucinite, a dimorph of variscite. 



Few new names are necessary, for varietal and other discarded 

 names may be used. In this paper I have recognized about twenty 



1 See paper by the author, "The Nomenclature of Minerals," Trans. Am. Phil. 

 Soc, LII (1013), 606-15. 



2 Centralblatt f. Min. Geol. u. Pal., 1913, p. 68. 



3 Ibid., pp. 517-18. 



