TALC-APATITE. 

 white, grey, dark-green, brown, and red. 

 Lustre pearly. Semi-transparent to sub- 

 translucent. Highly sectile. Li thin laminaj 

 flexible, but not elastic. Yields to the nail. 

 Streak white, or in dark-green varieties 

 paler than the colour. More unctuous to 

 the touch than Chlorite. H. 1 to I'o. S.G. 

 2-65 to 2-74. 



Comp. Silicate of magnesia, or Mg^ Si^ 



+ 2H- silica 62-14, magnesia 32-92 = 100. 

 Analysis, from Greiner, by v. Kobell : 

 Silica . . . \ . 62-8 

 Magnesia .... 82-4 

 Alumina . . . .1-0 

 Protoxide of iron, with oxide 



of titanium . . .1-6 

 Water 23 



100-1 



BB splits up into laminse, and hardens 

 without fusing. With microcosmic salt 

 yields a turbid glass, together with an in- 

 soluble skeleton of silica. 



Not acted on, to any perceptible degree, 

 either before or after ignition, by muriatic 

 acid or oil of vitriol. 



Localities. Greiner, in the Tyrol. Sala, 

 Fahlun, and other places in Sweden. Py- 

 renees. United States, &c. 



Brit. Mus., Case 32. 



Talc is a very generally diffused mineral, 

 and not only enters into the composition of 

 many crystalline rocks, but some of its va- 

 rieties form extensive beds in districts 

 occupied by crystalline rocks. The common 

 variety forms the basis of the rouge used by 

 ladies — the Talc being coloured by an ex- 

 tract from the Carthamus tinctorius, or 

 Safflnwer. In a powdered state it is also 

 employed to make new boots and gloves 

 slip on easily, and to diminish friction in 

 machinery. In its natural state it is used 

 by tailors for drawing lines on cloth. 

 For varieties of Talc and localities, &c., see 

 Indurated Talc, Talcose Slate, Soap- 

 stone or Steatite {Speckstein), Vene- 

 tian Talc. 



Brit. Mus., Case 32, 



M. F. G. Horse-shoe Case, No, 1170. 



Talc-apatite, Hermann. A variety of 

 Apatite containing magnesia. It occurs in 

 six-sided crystals in Chlorite-slate, on the 

 Schischimskian mountains, near Slatoust, 

 in the Ural. 



Comp. 3Cu5p + Mg3P. 

 Analysis, by Hermann : 



Lime . 



Phosphoric acid . 



37-50 

 3902 



TALKOID. 





Magnesia 



. 7-74 



Sulphuric acid 



. 2-10 



Chlorine 



. 0-91 



Oxide of iron 



. 1-00 



Fluorine and loss 



. 2-23 



Insoluble 



. 9-50 



371 



100-00 



Brit. Mus., Case 57 e. 



Talc Commun, Brochant. "] 



Talc Ecailleux, La 3Ie- y See Talc. 

 therie. J 



Talc Endurci, Brochant. Indurated 

 Talc (which see). 



Talc Geanuleux, Haiiy. See Na- 

 crite. 



Talc Graphique, Haiiy. See Agal- 



MATOLITE. 



Talc Mica, 3Iohs. Includes Potash- 

 Mica, Lithia - Mica, Biotite or Magnesia- 

 Mica, Talc and Chlorite. 

 Talc Ollaire, Haiiy. See Potstonje, 

 Talc Phosphorsaurer. See Wagner- 



ITE, 



Talc Steatite, Haiiy. Soapstone, See 

 Steatite. 



Talc Zographique, Haiiy. See Green 

 Earth. 



Talcite, Thomson. See Nacrite. Tal- 

 cite occurs in co. Wicklow, in Ireland, in- 

 vesting; and in the form of crystals of 

 Andalusite at Glendalough, Glen Malure, 

 and Longh Dan ; also at Mount Leinster in 

 Carlow, and Three Rock Mountain, co. 

 Dublin. 



Analysis, from Three Eock Mountain, by 



Kev, S. Haughton : 





Silica . 



, 43-47 



Alumina 



. 31-42 



Peroxide of iron , 



. 4-79 



Magnesia 



. 1-13 



Lime . 



. 1-38 



Soda . 



• 1-44 



Potash . 



. 10-71 



Water . 



, 5-43 



99-77 

 Talkartiger Diallag, Hausmann. 

 See Diallage, 

 Talkerde, Wei'uer. Magnesia, 

 Talkerde-alaun, v. Kobell. See Mag- 

 nesia Alum, 



Talkhydrat, v. Leonhard, Native Mag- 

 nesia. See Brucite. 



Tai.koid. The name given by Naumann 

 to sparry crystalline Talc from Presnitz, 

 where it occurs in snow-white, broad folia- 

 tions, with Magnetite. S.G. 2-48, . 



Comp. ''^Mgssi^ + H. 

 B B 2 



