400 VIVIANITE TEREEUSE. 



BB fuses very readily with intumescence 

 and loss of water, forming a grey, shining, 

 magnetic bead, and imparting a bluish- 

 green colour to the flame. 



Readily soluble in muriatic or nitric acid. 



Localities. English. — Cornwall : Huel 

 Kind, near St. Agnes, in very fine crystals on 

 Pyrrhotine, with small cryst-als of Siderite ; 

 Huel Falmouth, Kea ; Parknoweth and 

 Potallack, St. Just. Devonshire : at Huel 

 Betsy, near Tavistock; Huel Jane. Odin 

 mine, near Matlock, in Derbyshire. Isle of 

 Dogs, in mud. Foreign. — Bodenmais, in 

 Bavaria, in gneiss, with iron and Magnetic 

 Pyrites. The gold mines of Vorospatak, in 

 Transylvania. Kertsch, in the Crimea, in 

 the interior of shells. Isle of Bourbon. 

 Brazil. Imleytown, New Jersey, in fine 

 translucent dark blue crystals. Sicily. 

 Auvergne. 



See also Mullicite, Blue Iron Earth, 

 Anglarite. 



Name. After J. G. Vivian, English 

 mineralogist. 



Brit. Mus., Case 57. 



M. P. G. Horse -shoe Case, No. 

 361 A. 



Vivianite is much used as a colour by 

 carriage-painters. 



Vivianite terreuse. See Blue Iron- 

 Earth. 



VoGLiTE, Haidinger, Dana. Occurs in 

 aggregations of rhomboidal scales with a 

 ])early lustre. Colour from emerald-green 

 to bright grass-green. 



Comp. 2UC + CaC + Cu^ C^ + 14 H. 



Analysis, by Lindaher : 



Carbonic acid . . . 26-41 



Protoxide of uranium . 37-00 



Lime ..... 14-09 



Oxide of copper . . 8-40 



Water .... 13-90 



)9-80 



BB on charcoal, infusible alone. With 

 borax in the outer flame affords a pearl 

 Avhich is brown when hot, and becomes 

 brown and opaque when cool. 



Easily soluble in dilute muriatic acid. 



Locality. The Elias mine, near Joachims- 

 thal, in Bohemia, on Pitchblende. 



VoiGTiTE, Beudant. A mineral replacing 

 Mica in the granite of the western part of 

 Ehrenberg, near Ilmenau. It is nearly 

 almost always altered, and occurs in small 

 long and narrow leaves, of a leek-green 

 colour. Transparent in thin laminae. Lustre 

 pearly. Turns yellow or brown by decom- 

 position. H. above 2. S.G. 2-91. 



VOLKNERITE. 



Comp. 3 R si + ^" Si + 3 H, or like Bio- 

 tite all but the water. 



BB fuses easily to a Jblack glass, and 

 gives an iron reaction. 



Attacked by cold muriatic acid. 



VoLBORTHiTE, Hess, Dana, Nicol. Hex- 

 agonal. Occurs in small tabular crystals, 

 which are often aggregated in spherical 

 groups or foliated masses. Colour olive- 

 green ; grey. Translucent in thin splinters. 

 Lustre pearly to vitreous. Streak vellowish- 

 green, nearly yellow. H. 3. S.G. 3 46 to 

 3-86 (grey). 



Comp. Vanadiate of copper. 



Analysis, by Credner : 



Vanadic acid . . . o6*-58 

 Oxide of copper . . .44-15 



Lime 12-28 



Magnesia . . . .0 50 

 Protoxide of manganese . 0-40 



Water 4*62 



Gangue . . . .0-10 



98-63 



BB on charcoal, fuses easily without fume 

 or deposit, and, when more strongly heated, 

 solidifies in the form of a graphitic slag, 

 containing granules of metallic copper. With 

 carbonate of soda, on charcoal, immediately 

 yields copper. In borax or microcosmic 

 salt dissolves, and produces a beautiful 

 green colour. 



Dissolves in muriatic acid, with evolution 

 of chlorine. 



Localities. Sissersk and Nijni-Taguilsk, 

 in Siberia. Friederichsrode, in Thuringia. 



Name. After Dr. V. Volborth, of St. 

 Petersburg, by whom it was first recognised 

 as a distinct species. 



Brit. Mus., Case 38. 



Volcanic Glass. See Obsidian. 



Vulcanite. See Selensulphur. 



VoLGERiTE, Dana. A mineral occurring 

 as a white powder or crust with Cervantite, 

 of the alteration of which it is a result. 



Comp. Sb + 5H= antimony 60-3, oxygen 

 18-8, water 21-0 = 100. 



Name. After Volger, by whom it was 

 first analysed. 



VoLKNERiTB, Dana, Hermann. Occurs 

 in six-sided prisms with a perfect basal 

 cleavage ; also laiiiellar-massive. White. 

 Lustre pearly. Feels greasy. S.G. 2-04. 



Comp. Mg6 Al + 16 H. 



