VIOLAK 





nfijysis hy Dufrtnoy : 





Silica . . . . 



39-60 



Magnesia . . . . 



47-37 



Protoxide of iron . 



3-59 



Protoxide of manganese . 



2-42 



Lime . . . . 



0-63 



Potash . 



46 



Water . . . . 



5-80 



99-77 



BB infusible ; with 8 or 10 parts of borax 

 fuses to a green enamel. 



Soluble in strong acids. 



Locality. Traversella, in Piedmont, in 

 veins of Magnetic Iron-ore, accompanied by 

 lamellar Dolomite, Mica, Quartz, and dode- 

 cahedral crystals of Magnetic Iron-ore. 



Name. After Mons. Vi liars, author of a 

 Natural History of Dauphiny. 



Brit. Mus., Case 25. 



ViOLAN, Breithaupt A mineral resem- 

 bling Glaucophane. Occurs massive with 

 the cleavage of a slightlj^ oblique rhombic 

 prism. Colour dark vioiet-blue. Opaque. 

 Lustre waxy. Streak bluish-white. H. 6. 

 S.G. 3-23. 



BB fuses to a clear glass ; with borax in 

 the outer flame yields a brownish-yellow 

 glass, which is violet-red when cold ; in the 

 inner flame a yellow glass, colourless when 

 cold. 



It is found with Manganese-Epidote, at 

 St. Marcel, in Piedmont. 



Name. In allusion to its violet colour. 



Brit. Mus., Case 35. 



Vitreous Copper, P/ii7Zips."i See 



Vitreous Copper-Ore, > Copper 

 Kirwan. J Gi.ANCE. 



Vitreous Silver, Phillips; or Vitreous 

 Silver-Ore. See Silver Glance. 



Vitriol. The name used for the sul- 

 phates of the oxides of the metals. Hai- 

 [ dinger uses the term alone for Copper Vi- 

 I triol, or Cyanosite (which see). It is derived 

 j from vitrum (glass), because of its glittering 



like that substance. 

 i Vitriol bleierz, Werner. Lead Vitriol. 



I See Anglesite. 



Vitriol bleu, or Blue Vitriol. See 

 Cyanosite. 



Vitriol of Copper, Kirwan. See Cya- 

 nosite. 



Vitriol gelb. Potash Copperas. See 

 Gelbeisenerz. 



Vitriol de Goslar, See Gallizinite. 



Vitriol of Iron, Kirwan. See Cop- 

 peras. 



Vitriol de Plomb Natif, Brochant. 

 See Anglesite. 



VIVIANITE. 399 



Vitriol Ochre. See Pitticite. 

 Vitriol of Zinc, Kirwan. See Goslar- 



ITB. 



Vitriolite, Phipson. A variety of Green ; 

 Vitriol, in which a certain quantity of iron 

 is replaced by copper. Colour like sulphate 

 of copper when freshly broken ; but with a 

 green ochraceous tint externally, by long- 

 exposure to the air, owing to the peroxida- 

 tion of the iron. Crystalline form, that of 

 sulphate of iron. 



Comp. Sulphate of protoxide of iron, with 

 a small amount of sulphate of copper, or 



(FeCu)S5 + 7H. 



Analysis, by Dr. T. L. Phipson : 

 Oxide of copper . . . 15-86 

 Protoxide of iron . . 11-00 

 Sulphuric acid . . . 28-08 

 Water . . . .45-06 



lUOOO 

 Locality. The interior of Turkey, form- 

 ing large stalactites and mammillary masses 

 in a cave near a mine of Copper Pyrites. 



VivlANiTE, Allan, Dana, Dufrenoy, NicoL 

 Oblique. Occurs in oblique prisms, sometimes 

 exceedingly thin, and seldom terminated. 

 The crystals are of considerable length, and 

 often very small, aggregated, and diver- 

 gent. Frequently reniform and globular. 

 Structure divergent, fibrous, or earthy, also 

 incrustiiig. Colour pale green to indigo- 

 blue, darkening on exposure; generally 

 pale green by transmitted light, when 

 viewed at right angles to the axis, and 

 pale blue parallel with it. Transparent to 

 translucent. Lustra partly metallic, partly 

 vitreous. Streak bluish-white, changing to 

 indigo-blue on exposure to the air. The 

 colour of the powdered mineral in a dry 

 state is liver-brown. Flexible in thin 

 laminae. Sectile. Fracture not observable. 

 H. 1-5 to 2. S.G. 2-66. 



Fig. 453. 



Comp. Phosphate of protoxide of iron, or 



Fe3 P + 8 H = protoxide of iron 42-27, 



phosphoric acid 28-75, water, 28-98 = 100. 



Analysis, from St. Agnes, by Stromeyer : 



Protoxide of iron . . 41-22 



Phosphoric acid . . . 31-18 



Water .... 27-48 



99-88 



