452 



wherry: native element minerals 



Selenium, monoclinic. 

 Arsenic, monoclinic. 



Se 

 As 



COLLOIDAL GROUP. AMORPHOUS 



Carbon, amorphous C 



Silicon, dispersoidal Si 



Phosphorus, amorphous P 



Sulfur, amorphous S 



Selenium, amorphous Se 



Iodine, amorphous. 



Opisatel'noi Mineralogii, 1, 1908; Centr. 

 Min. Geol., 1912: 761; and still another 

 form in stable crystals has been de- 

 scribed by Suzuki, Beitr. Min. Japan, 

 5: 231. 1915. (Not in Dana.) 



'a-selenium " 



/"Arsenolamprite." Crystallization not 



\ certain. 



[New; includes all non-metals and semi- 

 l metals occurring in the amorphous 

 [ state. 

 The coloring matter of black sediments. 

 Suggested to be the cause of the color of 

 smoky quartz, though without state- 

 ment of evidence, by Konigsberger and 

 Muller, Centr. Min. Geol., 1906: 73, 

 note. (Not in Dana.) 

 Occurrence in nature reported by Ver- 

 nadskii, Opuit Opisatel'noi Mineralogii, 

 1, 1908; Centr. Min. Geol., 1912:762. 

 (Not in Dana.) 



"Sulfurite." A precipitate in sulfur- 

 spring water; also a volcanic product. 

 (Not in Dana.) 



Occurrence in nature pointed out by 

 Zambonini, Miner alogia Vesuviana, p. 

 24, 1910. (Not in Dana.) 



Occurrence in nature reported by Skey in 

 1877; Vernadskii, Centr. Min. Geol., 

 1912: 762. (Not in Dana.) 



METALS. 



COPPER GROUP. 



ISOMETIUC. 



Copper Cu 



Argentiferous. 

 Mercuriferous. 



Cu, Ag 

 Cu, Hg 



Includes the native elements of predomi- 

 nantly basic character. 



When the minerals of Dana's "gold 

 group" are arranged according to the 

 periodic system, copper comes first and 

 the group is here named after it. 



Wire copper, a variety, is probably a 

 paramorph of crystalline copper after 

 amorphous copper which has been 

 forced through small openings while 

 soft, corresponding to wire silver. 

 (See below.) 



[Brush, Am. Journ.Sci., [2], 31: 354. 1861, 

 | throws doubt on the occurrence of this 

 [ variety. 



