HUMBOLDTINE. 

 Comp. 3(Ca2, Si) + M bi^ (Gmelin). 

 2ii3 Si + ii" si (Dana) = fRS + JJJ) si. 

 Analysis, from Somma, by v. Kobell : 



Silica 43-96 



Alumina . . . .11-20 



Lime 31-96 



Magnesia . . . .6-10 



Soda 4-28 



Pota&h . . . . .0-38 

 Protoxide of iron . . - 2-32 



100-20 



BB fuses readily with slight evolution of 

 gas -bubbles, arid forms a blistered, trans- 

 lucent glass, of a somewhat greyer or more 

 greenish tint than the mineral. With borax 

 melts slowly to a colourless glass. Easily 

 decomposed by muriatic acid, with separa- 

 tion of gelatinous silica. 



Brit. Mus., Case 60. 



HUMBOLDTINE*, fariano^ Oxalate of 

 de River ; Brooke §• Muler. { , ^ 



HUMBOLDTITE*, Maker ^ ^ '^T:^Ji' 

 JSeuaant. J 



HuMBOLDTiTE*, Phillips. The name 

 given bj^ Levy to the Datholite found in 

 Agate-balls at the Seisser Alp in^ the Tyrol. 



Brit. Mus., Case 39. 



HuJiiTE, Bournon. A variety of Chon- 

 drodite found in ejected masses of a granular 

 or crystalline rock, on Monte Somma, with 

 brownish Mica, Olivine and Magnetite. Oc- 

 curs in minute but very distinct crystals of 

 a very variable colour, but generally yel- 

 lowish or deep reddish-brown, with a shining 

 lustre. Transparent or translucent. H. 6 to 

 6-5. S.G.3177 to 3-234. 



Fig. 235. 



Comp. Mg4 Si, with part of the oxygen 

 replaced by fluorine. 



Analysis^ by Rammelsherg : 



Silica 33-26 



Alumina .... 1-06 

 Magnesia .... 57-92 

 Protoxide of iron . . . 2-30 



Lime 0-74 



Fluorine . . . .6-04 



100-32 

 BB becomes opaque, but does not melt ; 

 with borax affords a clear glass. 



HURONirE. 181 



Name. After Sir Abraham Hume. 



Brit. Mus., Case o8a. 



HuNTERiTE, Haughton. A white fels- 

 pathic mineral, with a fatty lustre. Softer 

 than Felspar, but gritty under the agate 

 pestle. S.G. 2-3. 



Comp. Hj'drated tersilicate of alumina, 



with hyaline silica, or oAl Si^ + H Si^. 

 Analysis, by Haughton : 



Silica 65-93 



Alumina .... 20-97 



Lime 0-30 



Magnesia . . . .0-45 

 Loss by ignition . . . 11-61 



99-26 

 Locality. Near Nagpur in Central In- 

 dia, in a vein of pegmatite in gneiss. 



Name. After Mr. Hunter, by whom it 

 was brought to England. 



HuREAULiTE, Dufrmoy. An altered 

 form of Triplite, somewhat resembling Zir- 

 con in appearance. Oblique ; primary form 

 an oblique rhombic prism. In minute trans- 

 lucent crystals of a reddish-yellow colour, 

 slightly paler than hyacinth-red; violet, 

 brownish-orange, and rose-red. Lustre 

 bright. Optically biaxial. No cleavage. 

 Fracture conchoidal. H. 5. S.G. 2-27. 



Fig. 236, 



Fig. 237. 



Named after the Baron von Humboldt. 



Comp. (Mn, Fe)^ \^^. 



Analysis, by Damour, of yellow variety 



from the quarry of Vilate near Chanteloube : 



Phosphoric acid . . . 37-96 



Protoxide of manganese .41-15 



Protoxide of iron . . . 8-10 



Water 12-35 



Mixed sand . . . ,0-35 



99-91 

 BB gives off water when heated, and 

 fuses very easily to a black globiUe, having 

 a semi-metallic lustre. 



Name. After the locality, the Commune 

 of Hureaus, near Limoges, in Haute Vienne. 

 HuRONiTE, Thomson; T., S. Hunt. An 

 altered mineral near Fahlunite. Forms 

 spheroidal kidneys in rounded masses of 

 black Hornblende. Colour greenish-yellow. 

 Lustre resinous, passing into pearly. Trans- 

 lucent at the edges. Streak white. Frac- 

 n3 



