PHYSIOGRAPHY. 215 



Franklinite Gadolinite. 



Brittle. Acts upon the magnetic needle, but does not 

 exhibit magnetic poles. Hardness =6-0 . . . 6'5. Sp. gr. 

 = 5-091. 



Compound Varieties. Massive : composition granular, 

 strongly connected. 



1. Before the blow-pipe, alone on charcoal, it presents the appear- 

 ances of Magnetic Iron-Ore ; but with soda in a good reduction fire, it 

 emits the white smoke of Zinc, and becomes green when heated with 

 the same reagent upon platina-foil in the oxidation-heat of the instru- 

 ment. 



2. Analysis. 



By BERTHIER. By THOMSOX. 



Peroxide of iron - - 66-00 - - 66-10 

 Red oxide of manganese - 16-00 - - 0-00 



Oxide of zinc - - 17-00 - - 17-425 



Deutoxide of manganese - 0-00 - - 14-96 

 Silica 0-00 - - 0-204 



Water * 000 0-560 



3. Franklinite is found at Franklin furnace in Hamburg, (N. Jersey,) 

 accompanied by Red Zinc- Ore, Calcareous Spar and Garnet. The most 

 perfect crystals at this locality are imbedded in the Red Zinc-Ore ; those 

 engaged in the Calcareous Spar, and associated with Garnet, exhibit 

 rounded faces, resulting from the truncation of the solid angles of the 

 primary form. A more remarkable deposit of the present species oc- 

 curs at Stirling in the same region, where it exists in a powerful vein, 

 in which, cavities occasionally appear containing crystals of a very large 

 size, from one to three inches in diameter, and which are associated with 

 Troostite. 



GABBRONITE. (See Scapolite.) 



GADOLINITE. Hemi-prismatic 'Me lane- 

 Ore. PARTSCH. 



Primary form*. Oblique rhombic prism. M on M = 

 115. 



