A. F. Rogers — Collophane. 271 



The name, Collophane. 



In 1870 Sandberger gave the name Kolloplian to an 

 amorphous mineral containing calcinm phosphate, cal- 

 cium carbonate, and water from the island of Sombrero 

 ("West Indies). The calcinm carbonate was believed to 

 be an impurity and so was deducted from the analysis 

 which on recalculation gave the formula, Ca 3 P 2 O s .H 2 0. 



As Lacroix 7 first pointed out, the calcium carbonate is 

 an integral part of the mineral. Specimens free from 

 admixed calcite effervesce vigorously when treated with 

 hot nitric acid. On calculation the Sombrero mineral 

 yields the formula 3Ca, H (P 2 8 ).CaC0 3 3H 2 0, but it is sim- 

 ply a coincidence that the amount of water is 3 molecules. 

 Analyses of specimens from other localities prove that 

 the water is variable. The ratio of calcium phosphate to 

 calcium carbonate is also variable and some specimens 

 contain fluorine and the sulphate radical. 



Dana changed Sandberger 's name Kolloplian to collo- 

 plianite. The writer prefers collophane, which is simpler 

 and more euphonious. As Cole s has well said : ". . . the 

 terminology of minerals formerly possessed, for the 

 founders of the science, as agreeable a variety as that of 

 other branches of natural history. There seems no need 

 to make technical language harsh by the undue repetition 

 of sounds that have no historic warrant. ' ' 



Synonyms of Collophane. 



Kollophan, Sandberger, 1870. 

 Apatite (in part). Most authors. 

 Collophanite, Dana, 1892. 

 Colophanite, Lacroix, 1910. 

 Fluocolophanite, Lacroix, 1910. 

 Collophane, Rogers, 1917. 

 Pyroclasite, Shepard, 1856. 

 Pyroguanite, Shepard, 1856. 

 Glanbapatite, Shepard, 1856. 

 Sombrerite, Phipson, 1862. 

 Monite, Shepard, 1882. 

 Floridite, Cox, 1890. 

 Quercyite, Lacroix, 1910. 

 Odontolite (Bone tnrquois) 

 Xauruite, Elschner, 1913. 



e Neues Jahrb. Min., 308, 1870. 



7 Comptes Eendu, 150, 1213, 1910. 



8 Outlines of Mineralogy for Geological Students, p. 169, London, 1913. 



