A PRELIMINARY REPORT ON THE MICROSCOPY 

 OF ANTHRACITE COAL 



HOMER G. TURNER and H. R. RANDALL 

 Lehigh University 



INTRODUCTION 



In connection with petrographic studies during the winter of 

 1921-22, the authors became interested in the microscopic character- 

 istics of anthracite coal. A review of the Hterature, however, 

 revealed the fact that very little had been accomplished in this 

 field. The reason appeared to be the inabihty to prepare specimens 

 that would show their microscopic structures. An investigation 

 was therefore begun which had as its purpose the treatment of 

 anthracite so that its microscopic features could be easily discerned. 

 The results of the method finally adopted are revealed in the 

 accompanying photographs which show some of the most conspicu- 

 ous structures observed. While no attempt is made at this time to 

 classify definitely the organic forms, some tentative conclusions 

 nevertheless seem warranted from the observations thus far made. 



The coal used in connection with this investigation came from 

 the Northern, Western Middle, and Southern Fields of the Penn- 

 sylvania anthracite region. Specimens from the Buck Mountain, 

 Primrose, and Mammoth beds from each field were studied. 



METHODS ADOPTED 



After considerable experimentation with thin sections and 

 various chemical reagents, with unsatisfactory results, the method 

 herein described was developed. It consists briefly of obtaining a 

 polished surface on the coal and etching with heat. Although 

 pieces of various sizes and shapes are used, blocks of coal about 

 two centimeters square take the most uniform polish and are large 

 enough to be handled with ease. Larger pieces can be used provided 

 that one has the equipment for pohshing them, and such may be 



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