PREFACE 



Tin. object of this book is to bring together for the beginner, in 

 jncise form and under one cover, the facts and basic principles of 

 the several branches of mineralogy, unadulterated by an excess of 

 data. It is, therefore, not a book of reference, but it takes the stu- 

 dent along the various branches of the subject to a point from which, 

 if he wishes to continue, he will be in a position to appreciate and to 

 use the advanced literature and books on the subject. 



The system of Dana has been followed to a great extent, as that is 

 the book of reference which is largely used by the American stu- 

 dent, though other sources have been freely consulted in the com- 

 >ilation of this volume. In Part I, Crystallography, the thirty-two 

 types have been described for completeness, even though there are 

 10 minerals crystallizing in some of them. The names used are 

 those of Miers, as they embody the symmetry of the type and thus 

 require very little memory on the part of the student. Dana's 

 names are given in each case under the term "class." 



The old method of deriving the hemihedrons, etc., from the holo- 

 hedrons has been retained and may meet with criticism, but it is a 

 simple method of determining what forms are possible to combine 

 on crystals of lower symmetry. I have always found it a very mate- 

 rial aid to the student, leaving no false impressions. 



Only graphical methods of solving the problems, after the meas- 

 urement of a crystal, are given, and the mathematical solutions are 

 left to the more advanced courses. 



In Part II, a knowledge of general chemistry is presupposed. 

 Here some two hundred and twenty-five mineral species are included 

 in the general descriptions, embracing the common rock-forming and 

 ore minerals. Their crystallization, optical properties, decomposi- 

 tion products, genesis, occurrence, uses, and synthesis are included 

 in the short description of most of the species. 



The determinative tables and chemical tests used in the blowpipe 

 table for the identification of the elements are included in Part III. 

 This table includes all minerals with the exception of some very 

 rare species found only in one locality, and in many cases includes 

 even these. It therefore serves the purpose of placing before the 



