750 



REPORT OF NATIONAL MUSEUM, 1897. 



Wolframiie. — Chiefly ferrous tungstatc, with some mauganese. It occurs in irregu- 

 lar lamellar, coarso divergent columnar, and granular masses, and in crystals, com- 

 monly tabular. Color and streak nearly black. Wolframite is often associated with 

 tin ores, and with quartz carrying bismuth, sclieelitc, pyrite, galena, sphalerite, etc. 



Hiihnerile. — Chiefly manganese tungstate, with some iron. It occurs in bladed 

 forms and massive in quartz, and with alabandite, rhodonite, scheelite, fluoritc, and 

 apatite. Color brownish red, hair brown to nearjy black. Streak yellowish brown. 



Following the group label, arranged iu order from left to right, are 

 tlie several members of tlie group, selected to illustrate as completely 

 as possible their occurrences, associations, and variety in form aiid 

 color. Each specimen is mounted upon a block, in front of which is a 

 small label giving the name of the species, the minerals associated with 

 it in that particular specimen, if any, its locality, catalogue' number, 

 and from wliom and how received. 



The several grou])S are placed in regular order in the cases, and each 

 case carries a case label giving the name of the class to which its con- 

 tents are referred. In the upper left-hand corner of each case is a 

 numeral followed by an arrow, which serves to indicate the sequence 

 in which the cases are to be studied, and also to facilitate leference to 

 the text of a descriptive catalogue to be printed. 



CLASSIFICATION. 



I. ELEMENTS. 



Of the seventy or more elements at present known to chemistry but 

 eighteen, excluding those occurring only in the gaseous state, are found 

 native. With the native elements are included the native alloys, or 

 compounds and mixtures of elements belonging to the same groups in 

 the periodic system. 



Group 1. 



Diamond. C. Isometric; tetrahedral. 



l?ort. 



Carbonado. 

 Graphite. C. Hexagonal; rliombohedral. 



Schungite. 



Graphitoid. 

 Cliftouite. 



Sulphur. 



Selen sulphur. 



Tellur sulphur. 

 Selenium. 

 Tellurium. 



Selentellurium. 



Arsenic. 



Arsenolamprite. 

 Allemontite. 

 Antimony. 

 Hismuth. 



Group 3. 



S. 

 (Se,S). 

 (Te,S). 



Se. 



Te. 



Group 3. 

 As. 



(As.Sb). 

 Sb. 

 Bi. 



Orthorhombic. 



Hexagonal; rhombohcdral. 



Hexagonal; rhombohedral. 



Hexagonal ; rliombohedral. 

 Hexagonal; rhombohedral. 

 Hexagonal; rhombohedral. 



