I9I3] ROGERS— THE NOMENCLATURE OF MINERALS. 615 



bonamite, ricolite, satelite, and vredite are trade-names of semi- 

 precious and ornamental stones. Aglaurite (orthoclase), bravoite 

 (pyrite), hallerite (paragonite), cobaltocalcite (calcite), isomicro- 

 cline (microcline), loaisite (scorodite), neslite (opal), magnesium- 

 pectolite (pectolite), pulleite (apatite), tawmawite (epidote) are 

 simply varieties of the minerals indicated. Still other names are 

 synonyms but these are often unavoidable. 



The task of descriptive mineralogy is to establish and define the 

 distinctive minerals or mineral species but the science is greatly 

 handicapped by hundreds of varietal names which are worse than 

 useless. 



In conclusion let me urge that in the future new names be given 

 to bona fide mineral species only and that distinctive names of 

 varieties, pseudomorphs, and mixtures be discarded as far as possible. 



Stanford University, California. 

 May, 1913. 



