DIRFXTIONS FOR COLLECTING MINERALS. 



By "Wirt Tassin, 



Assistant Curator of the Department of Minerals. 



GrENERAL REMARKS. 



The value of a mineral collection depends largely upon the quality of 

 the specimens and upon the completeness of the information concern- 

 ing them. A bruised or scratched specimen, or a broken crystal, has 

 little to recommend it, and a mineral of unknown locality or undefined 

 associations can be admitted to a cabinet only under protest. With 

 regard to any given species, the geographical and geological distribu- 

 tion is an important fact; and it is therefore desirable, in each locality, 

 to collect every variety which can be found. Specimens which would 

 be worth little by themselves become valuable when studied in relation 

 to others, and a common mineral, found under unusual circumstances, 

 may have exceptional interest. 



WHERE TO LOOK FOR MINERALS. 



The best field for a collector is always that which has been well 

 opened, such as a mine, a quarry, a railroad cut, etc. Fresh exposures 

 of unweathered rock yield the best specimens. In prospecting, how- 

 ever, where no work has been j)reviously done it is desirable to get 

 below the weathered rock surface to the fresh material beneath. Some- 

 times nature assists in this direction, as in ravines and along the bases 

 of cliffs where, in early spring, rock falls leave clean exposures. The 

 recent talus at the foot of a cliff affords a good field for examination. 



IMPLEMENTS USED IN COLLECTINa. 



The tools used in collecting minerals are few in number. The first 

 and most indispensable tool is a hammer (see fig. 1). It should be of 

 well tempered steel, weighing about two pounds, with the striking face 

 square and the cutting edge having the same direction as the handle. 

 The handle should be made of good hickory and wedged into the head 

 with iron wedges. A foot scale, divided into inches, marked on tlie 

 handle, is desirable. 



It often happens that upon specimens brought in from the field there 

 is an unnecessary amount of the gangue adhering, or part of a crystal 

 or crystals may be covered up by the matrix. This can readily be 

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