212 



University of California. 



[Vol. 3. 



CHALCANTHITE. 



General Description . — Chalcanthite is, next to pisanite, the 

 most abundant secondary mineral in the mine. It occurs as 

 drusy coatings on the massive ore and on the timbers of the 

 mine, and as loose crystals. The loose crystals are of a dark 

 blue color, while the drusy coatings vary in color from a light 

 blue to a pale green. 



Crystallographic Characters. — The crystals vary in size, the 

 drusy crystals being very small, while the loose dark blue crys- 

 tals average about 1X3X5 mm. Many, however, are very 

 much larger, the largest one found measuring 4X10X35 mm. 

 Most of the crystals are not rich in forms, but occasionally a 

 crystal was found which showed quite a rich combination. The 

 following fourteen forms were observed on the seven crystals 

 measured, two of which, / = \ 120 ( and g = |141|, are new: 



Letter. 





Symbol. 



Letter. 



Symbol. 





Gdt. 



Miller. 





Gdt. 



Miller 



C 







00] 



V 



01 



Oil 



b 



Ooo 



(111) 



'1 



02 



021 



a 



oo 



100 



w 



03 



031 



m 



cc 



111] 



I 1 



TO 



101 



1 



x>2 



120 



s 



11 



Til 



M 



oo^o HO 





13 



T31 



h 



oo 2 



120 



9 



14 



141 



The measurements, with the calculated values, taken from Gold- 

 schmidt's Winkeltabellen, are given in the following table: 



1 





Symbol. 



Measured. 



Calculated. 



Lett 



Gdt. 



Miller. 





P 



<#> 



P 



1 



c 







001 



31 



D 57' 



29° 



59' 



31 



3 54' 



29° 



46' 



2 



h 



Ooc 



1)1(1 







00 



90 



00 







00 



90 



00 



3 



a 



ooO 



100 



79 



16 







79 



19 



J7 





4 



m 



00 



110 



53 



03- 







53 



03 



17 





5 



I 



oo 2 



120 



37 



10 







37 



14 



77 





G 



M 



oo oo 



1T0 



110 



34 







110 



33 







7 



h 



oo2 



120 



133 



11 







133 



11 



JJ 





8 



V 



01 



(111 



16 



45 



47 



55 



15 



56 



47 



45 



9 



'/ 



02 



021 



154 



48 



35 



24 



155 



24 



35 



59 



10 



w 



03 



031 



165 



52 



51 



25 



166 



13- 



51 



47 



11 



p 



TO 



T01 



67 



02 



37 



30 



67 



39 



37 



41- 



12 



s 



Tl 



Til 



39 



08 



48 



46 



39 



30 



48 



19- 



13 





T3 



T31 



T53 



27 



56 



29 



153 



22- 



57 



54 



14 



9 



14 



141 



140 



36 



64 



32 



140 



45 



64 



23 



