Introduction to Tables. 93 
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INTRODUCTION TO THE ANYLATICAL TA- 
BLES OF MINERALS. 
The names of minerals as they appear in the fol- 
lowing tables are grouped according to the most promi- 
nent metal, or element, entering into their composition. 
Brief descriptions of each mineral as given in the tables 
are of typical specimens and they are arranged in the 
following order: In the first column is found the names 
of the minerals; in the second column, their chemical 
composition (deduced from formule or analyses) ; in 
the third, lustre, ete. 
Determination of Minerals By the Tables.—To do 
this test the specimen to be determined very carefully, 
and ascertain its physical properties; form some idea 
of the group to which it belongs (i. e., whether a lead 
mineral, silver mineral, copper mineral, etc.), and note 
on a slip of paper the following: First, the Group; 
second, note its Lustre; third, its Color; fourth, Hard- 
ness (H); fifth, Streak; sixth, break and note 
its Fratcture and Cleavage; seventh, note (when 
breaking) its Tenacity ; eighth, if not otherwise 
recognizable, examine with a magnifying glass, and 
note its Crystalline System (Crys. Syst.) ; ninth, note 
its Fusibility by holding a small splinter of the min- 
eral with one end held between the points of the plati- 
num forceps and the other in the reducing flame (R. F.) 
of the blowpipe; note the degree by which its edges be- 
come rounded and by which the splinter is consumed, or 
