variscite; 





Protoxide of iron 



. 



11-07 



Lime . 



, 



5-90 



Magnesia . 



. 



9-Ul 



Soda . 



. 



3'07 



Potash . 





1-16 



Water and carbonic 



acid 



4-38 



98-54: 



Analysis, by Delesse, 



of the 



spher 



(S.G. 2-923) : 







Silica . 





56-12 



Alumina 





17-40 



Peroxide of iron . 





7-78 



Oxide of chrome . 





0-51 



Lime . 





8-74 



Magnesia 





3-41 



Soda . 





3-72 



Potash 





0-24 



Water . . 





1-93 



99-85 



Variscite, Breithaupt. An apple-green 

 mineral with a weak resinous lustre, and a 

 greasv feel, forming a reniform incrustation 

 on flinty slate at Messbach, near Plauen, in 

 the Voigtiand It is considered by Plattner 

 to consist of alumina and phosphoric acid, 

 •with ammonia, magnesia, protoxide of iron, 

 oxide of chrome and water. 



The word Variscite is derived fi'om 

 Variscia, the Latin name of Voigtiand. 



Varvacite, Thomson. Varvicite, i?. 

 Phillips. Probably a mixture of Pyrolusite 

 and Psilomelane, or Manganite ; the former 

 of which it resembles in hardness and the 

 colour of its powder, and the latter in ap- 

 pearance. It is found at Hartshill, in 

 Warwickshire, in slightly radiating, fibro- 

 lamellar masses, of a steel-grey colour. 

 Lustre submetallic. H. 2-5 to 3. S.G. 4*3. 



Analysis, by R. Phillips : 



Manganese .... G3-3 



Oxygen 31-7 



Water 50 



100-0 



Name, The name Varvicite was devised 

 by the late Richard PhiUips, to facilitate the 

 pronunciation by foreigners of the Avord 

 Warwick ( Varv'ic), the locality after which 

 the mineral was called. 



Vauquelixite, Dana, Nicol, Phillips, 

 Steffens. Oblique. Occurs in irregularly 

 aggregated, minute and generally macled 

 crystals, or in mammillated masses forming 

 tliin crusts, which are sometimes hollow 

 and approaching to stalactitic. Colour 

 black (occasionally with a tinge of green) 



VENUS' HAIR-STONE. 397 



or brown. Faintly translucent or opaque. 

 Lustre adamantine to resinous : faint in the 

 brown varieties. Streak siskin-green or 

 brownish. Rather brittle. Fracture uneven. 

 H. 2-5 to 3. S.G. 5-5 to b-8. 



Fig 450. Fig. 451, 



Comp. Chromate of copper and lead, or 



Cu3Cr2+2Pb5Cr2.= oxide of copper 10-9, 

 oxide of lead 61*2, chromic acid 27-9 = 100. 



Analysis, from Beresow, by Berzelius : 

 Oxide of lead . . . 60 87 

 Oxide of copper . . . 10-80 

 Chromic acid . . . 28-33 



• 100-00 



BB on charcoal swells up slightly, and 

 then fuses with strong intumescence to a 

 dark grey globule, with a metallic lustre, 

 and surrounded with small granules of 

 metal. With borax and microcosmic salt 

 in small quantity, dissolves with intumes- 

 cence, and forms a green glass which, if sub- 

 jected to the action of the inner flame, and 

 then left to cool, becomes red, opaque-red, 

 or black according to the quantity of the 

 iuineral : a large qitantity of the" mineral 

 forms a black globule with borax imme- 

 diately. 



With nitric acid forms a dark green 

 solution, and leaves a yellow residue. 



Localities. Beresow in Siberia, on Quartz, 

 accompanied by Crocoisite (chromate of 

 lead). Pont Gibaud, in the Puy de Dome 

 (Auvergne). Brazil, with Crocoisite, at 

 Congonhas do Campo. The Sing-sing Lead 

 mine in l^ew York. 



Name. In compliment to the French 

 chemist, Vauquelin. 



Brit. Mus., Case 39. 



Velvet Blue Copper Ore, Jameson. 

 See Lettsomite. 



Venetian Talc, Jameson, Kirwan. A 

 kind of indurated common Talc or Stea- 

 tite, used, when reduced to powder, for 

 making the coloured crayons called pastels. 

 The same mineral powdered and coloured 

 with a little' safiiower, constitutes the cos- 

 metic called Fard. 



Venus' Hair-stone. A name for pure 

 Rock Crystal, containing included hair-like 

 filaments, or long acicular crystals of Tita- 

 nium ; found in Madagascar and Brazil. 

 This is the true Venus' Hair-stone; but the 



