NO. 2060. WOLFRAMITE, BERAUNITE, AND AXINITE— WHERRY. 505 



ferred to the use of distinct names for the end members because, 

 while both are ambiguous in being ordinarily used for quite distinct 

 things, it seems simpler to restrict the chemical terms to one mean- 

 ing. Thus, both ferrowolframite and ferberite may be used either 

 for pure ferrous tungstate, or for a ferrous tungstate containing a lit- 

 tle manganese isomorphously replacing the iron ; mangano wolf rami te 

 and hiibnerite for either pure manganese tungstate or manganese 

 tungstate containing a few per cent of iron in isomorphous replace- 

 ment; cuproscheelite and cuprotungstite for various mixtures of cop- 

 per and calcium tungstates, etc. 



If mineralogy is ever to have anything like a quantitative system 

 of nomenclature, such ambiguity will have to be avoided, and it 

 seems to the wi'iter that the best way to avoid it will be through 

 restricting the use of words with chemical prefixes to the end mem- 

 bers, whether found in nature or not, and doing away with distinct 

 names for them. The method used in the well-known quantitative 

 classification of igneous rocks could be adopted here, using the pre- 

 fixes: Permangano when Mn: Fe is greater than 7: 1; domangano 

 between 7 : 1 and 5:3; f erromangano between 5 : 3 and 3:5; dof erro 

 between 3: 5 and 1:7; and perferro less than 1 : 7. Named according 

 to this plan, the wolframite from Cornwall would be ferromangano- 

 woKramite and that from Cave Creek dof erro wolframite. Such names 

 are of course too cumbersome for everyday use, although it is possi- 

 ble that in certain cases they might be employed with advantage for 

 purposes of classification or comparison. It is especially urged, 

 however, that they, like those of end members, be omitted from lists 

 of mineral names, for arbitrarily partitioned-off portions of isomor- 

 phous series are not to be regarded as definite minerals. 



It is of course impossible to refer in the names to aU constituents 

 of the minerals, but that does not mean that some of the minor ones 

 are not of considerable importance; and the significance of the colum- 

 bium and tantalum found in these samples is certainly worth dis- 

 cussing. In the table of calculated mineral compositions these have 

 been regarded as united with iron and manganese, to form the colum- 

 bite and tantalite molecules. No columbite and tantalite are present 

 as visible inclusions, for the brilliant cleavage surfaces of the wolfram- 

 ites look perfectly uniform under the microscope. But they might 

 exist either 1, in chemical combination; 2, as submicroscopic inclu- 

 sions; in one of the types of soUd solution: 3, isomorphous replace- 

 ment; or 4, mix crystals; or, finally, 5, as an adsorption compound. 

 The tendency of the " metallic acids" — columbium, tantalum, tita- 

 nium, tungsten, vanadium, etc. — to enter minerals in these ways is 

 very evident when the variability in composition of many colum- 

 bates, of the titaniferous magnetites, etc., is considered. But vari- 

 ous interpretations have been put on it by differeiit observers. 



