BY W. F. PETTERD, C.M.Z.S. d 



have received distinctive appellations, are absolutely with- 

 out intrinsic value. It may be said, without danger of 

 a serious perversion of fact, that of the enormous number 

 of mineral substances which are already known to science, 

 not two per cent, have any direct or indirect commercial 

 importance : but as products of Nature's handiwork all are 

 worthy of the study and attention of the chemist, the 

 petrologist, and those interested in natural science. The 

 mineralogist is always engaged in revelling in the mysteries 

 of his study, yet it is ever evident that each fresh discovery 

 still further impresses him with the fact that there is yet 

 more to learn, even about what are apparently the most 

 simple substances. 



Any explanation of the larger and more abstruse subject 

 of the genesis of ore-deposits has not been seriously under- 

 taken, as that is a task for the advanced specialist, who 

 would need much collateral information, both local and 

 scientific, on which to formulate any rational theories as 

 tb the varied conditions which govern the deposition of 

 minerals in the different classes of lode formation and 

 filling. 



From the last published Catalogue several species have 

 been eliminated, either because their occurrence in this 

 island has not been confirmed, or that their presumed 

 identification was in error ; but to compensate for this a 

 large number — considerably over 100 — have been added. 

 Some few of these had been overlooked, but the greater 

 number are the result, as already indicated, of investiga- 

 tion during the past few years. 



The number of species and varieties of minerals herein 

 referred tc is approximately 330, which may be regarded 

 as a remarkably large number, considering the com- 

 paratively restricted area of the island. Although this 

 number may, and doubtless will, be augmented as investi- 

 gation proceeds, it is reasonable to suppose that we now 

 possess a fair knowledge of the mineralogy of the State, 

 thanks to the services rendered and encouragement given 

 by willing helpers. 



The writer is under personal obligation for information 

 to Messrs. R. Sticht, L. K. Ward, O. E. White, W. R. Bell 

 W. E. Hitchcock, and several others, who by giving 

 localities and forwarding specimens have rendered valu- 

 able assistance, and it is to his friend Mr. W. H. Twelve- 

 trees that his special thanks are due for so much kindly 

 advice and help, which have mat-erially lightened his self- 

 imposed task. 



January 18, 1910. 



