228 UNIVERSITY OF VIRGINIA PUBLICATIONS 



silica of the original wood itself, obviously provided all the necessary ele- 

 ments to form evansite and so, perhaps, explains how it happens to be pres- 

 ent in this association. The analysis which follows gives the composition 

 of the coal in which it occurs. 



Analysis of bulk sample of the Martin coal seam. 



Per cent 



Moisture 0.90 



Volatile matter 28.90 



Fixed carbon 45 . 00 



Ash 25.20 



Sulphur 6.43 ' 



The argillaceous matter in the Martin coal seam, as indicated by the 

 high content of ash, is finely disseminated through it; partings of slate and 

 other macroscopic eviden^ce of its presence being lacking entirely. The 

 high ash content is, therefore, a defect in its quality for which one is not' 

 apt to be all prepared and analj'ses showing how large a per cent of it is 

 inert, obviously, occasion considerable surprise. 



The appearance of the evansite from the opening on the Martin coal 

 seam near Coalville, Alabama, is well shown by the accompanying photo- 

 graph taken by Holsinger of Charlottesville, Virginia, of the specimen 

 presented by the writer to the Geological Department of the University 

 of Virginia. It is perhaps the only specimen of its kind in any laboratory 

 in the world. Since the coal shaft from which it was obtained has long 

 since been abandoned and is now filled with water it would be both difE- 

 cult and expensive to duplicate it. Though scarcer than diamond it has, 

 however, no special economic value but it is to be highly prized neverthe- 

 less because of its rarity as a mineralogical specimen — especially as asso- 

 ciated with coal. 



As Mr. Charles Catlett* remarks, in his paper previously referred to, 

 "One form in which phospfeorus occurs in coal is evidently as a hydrated 

 phosphate of aluminum; and any coal which shows to the ej^e the occurrence 

 of a light-colored resinous-looking material should be looked on with sus- 

 picion as being high in phosphorus." In other words it is not improbable 

 that a good per cent of the substances found in coal and labelled resin 

 may, when their pyrognostic characteristics are more carefully determined, 

 prove to be evansite which some of the resins so closely resemble. 



One of the specimens given him (Catlett) by the writer was "purified 

 down to about 0.3 g" and was analyzed by Professor John J. Porter of the 

 University of Cincinnati with the following result : 



* Bull.59,A.I.M.E. 



