vi PREFACE 



student a nearly complete list of the mineral species with their 

 chemical formula, hardness, color, crystallization, and specific grav- 

 ity. The table has been arranged after years of experience in 

 teaching blowpipe analysis, and only those tests are employed and 

 described which are quite easily manipulated, and wherever possible 

 the dry or blowpipe tests are given the preference. In its scheme it 

 is inodeled after Brush and Cornwall's determinative table. 



The table for the determination of the common minerals by use 

 of their physical properties includes about one hundred and fifty 

 species, and in connection with the short descriptions of these species 

 given in Part II, makes their identification a simple matter. 



Table I includes about fifty species of the rock-forming min- 

 erals arranged for their identification in rock sections under the 

 microscope. 



The illustrations, with the exception of two, have been drawn by 

 the author, and the photographs reproduced are of specimens in the 

 collection of Princeton University. 



For advice and assistance in this work my sincere thanks are due 

 to many of my colleagues, but particularly to my esteemed friend 

 and professor, Henry B. Cornwall. 



ALEXANDER HAMILTON PHILLIPS. 



PRINCETON, NEW JERSEY, 

 September, 1912. 



