Washington — Suggestion for Mineral Nomenclature. 147 



or acid salts they may be so designated, but in general they 

 may be designated by special acidic names for the group, since 

 the acidity or basicity almost always determines a crystal form 

 different from that of the normal salt. 



Names formed as suggested above have certain analogies 

 with some of the present mineral names, in which isomorphous 

 replacement is indicated by the use of chemical modifiers, as 

 soda-microline, manganopectolite, cuprodescloizite, natrojaro- 

 site, plumbo-jarosite and soda-mica. Even in these we can see 

 the lack of system in present nomenclature, since these names 

 belong to two distinct categories. In the one the modifier 

 expresses only partial replacement of the characteristic element 

 of the type mineral by an isomorphous one, as in the first three 

 examples, which are presumably cases of solid solution and 

 should be regarded as varieties of the type, or as intermediate 

 between two extremes. In the last three cases there is entire 

 replacement by the element denoted in the name, and such 

 minerals are definite compounds and must be regarded as dis- 

 tinct species. For this reason natrojarosite and plumbojarosite 

 are better entitled to recognition as distinct minerals than are 

 soda-microcline (anorthoclase) or manganopectolite, and should 

 have special names not formed on this plan, while paragonite has 

 properly replaced the earlier soda-mica, which last should be 

 used for a mica in which the potassium is only partially replaced 

 by sodium. 



The names of the suggested nomenclature are properly appli- 

 cable only to minerals of the second kind just mentioned, that 

 is to definite compounds, since it is essentially an inorganic 

 chemical nomenclature, in which mixed crystals should be 

 named by calling them mixtures of their components. In 

 mineralogy the case is somewhat different, it is true, as such 

 mixed crystals are often important and fairly well-defined min- 

 eral species, and names for them are necessary. Some latitude 

 and discretionary power must, therefore, be allowed, and while 

 all rather indefinite mixed crystals need not receive specific 

 recognition or names, there will be many cases, especially 

 when the mixture is of mineralogical importance, fairly con- 

 stant in composition, or with some approximation to simple 

 stoichiometric ratios, when names as above should be bestowed. 

 To meet the common case of the indefinite or variable isomor- 

 phous replacement, it may be suggested that the syllable -io be 

 added to the compounded elemental syllables used for the base. 

 Thus the various hypersthenes and bronzites would be called 

 collectively fermagic hypersthenates, and the lime-soda feld- 

 spars would be calsodic albates. 



Illustrations of the System. — It is impracticable to give 

 here a complete illustration of the application of the system to 



