SLATE CLAY. 



Whitehaven, is of this description ; as also 

 much of that in the districts of the Forth 

 and the Clyde, in Scotland, as well as of 

 Dumfries- shire. See Hard Coal. 



Slate Clay, Jameson, Kirwan. See 

 Shale. 



Slate Spar, Jameson. A massive variety 

 of carbonate of lime, occurring in very thin 

 parallel lamina, of a milk-greenish or red- 

 dish-white colour. It is friable, soft, and 

 tender, and has a pearly lustre. Translucent. 

 Yields easily to the knife, and often feels 

 greasy. S.G. about 2*5. 



Localities. — English. Cornwall : at Botal- 

 lack, near St. Just ; Delabole, near St.Teath ; 

 Xorth Roskear ; and Folgooth Mine, Beerai- 

 ston, in Devonshire. Coniston United Mine, 

 Lancashire. — Scotch. Strontian, Argyll-- 

 shire. Glen Tilt, Perthshire. Assynt, 

 Sutherland . — Irish. Co. Wicklow ; at Glen- 

 dalough and Lugganure lead mines. Kil- 

 kenny. Carlow. Kildare. — Foreign. Konigs- 

 berg, in Norway. Bergrun, near Schwar- 

 zenberg, in Saxony. 



Brit. Mus., Case 45. 



Slaty Coal. See Slate Coal. 



Slaty Copper Ore, Kirwan. Kupfer- 



SCHIEFFER. 



SLOA^'ITE, Ileneghini §• Bechi. Occurs 

 in white and opaque radiated masses, Avith 

 a pearly lustre, and frequently a fracture 

 transverse to the radiations. H. 4-5. S.G. 

 2-44. 



Comp. (CaMg)5 Si2 + 5 Al si + 9H. 



Anali/sis, by Bechi : 



Silica 42-19 



Alumina .... 35*00 

 Lime . . . . . 812 

 Magnesia . . . . 2-67 



Soda 0-25 



Potash 0-30 



Water ..... 12 '50 



101-03 



BB swells up and fuses to a white enamel. 



Soluble in acids, forming a jelly of silica. 



Locality/. Tuscany, in gabbro rosso. 



Name. After Mr. Henry Sloane, pro- 

 prietor of the mine of Monte Catini, in Tus- 

 cany. 



Fig. 390. 

 Smaltine, 



Fig. 391. Fig. 392. 



Beudant, Haidivger, Nicol. 



SMALTINE. 349 



Cubical, with a cleavage parallel to the faces 

 both of the octahedron and cube. Occurs 

 in octahedrons, cubes, and their modifica- 

 tons ; also in reticulated, arborescent, botry- 

 oidal reniform and amorphous masses. Colour 

 tin-white inclining to steel-grey Avhen mas- 

 sive, and sometimes with a superficial grey- 

 ish or iridescent tarnish. Opaque. Lustre 

 metallic. Yields to the knife with difficulty. 

 Streak greyish -black. Brittle. Fracture 

 fine-grained and uneven. H. 5 "5 to 6. S.G. 

 6-46 to 77. 



Comp. Arsenide of cobalt, or (Co,Fe,'Ni) 

 As — cobalt 9'4, iron 9-0, nickel 9*5, arsenic 

 72-1 = 100. 



Analysis, from Joachimsthal, by F. 3Ia- 

 rian : 



Arsenic 74*52 



Cobalt 11-72 



Iron 5*26 



Nickel 1*81 



Copper 1-00 



Sulphur . . . . 1*81 



96*12 



BB on charcoal gives off copious arsenical 

 fumes, and fuses to a white, brittle, metallic 

 globule, which after being roasted imparts 

 a blue colour to glass. 



Soluble in hot nitric acid, with separation 

 of arsenious acid. 



Localities. — English. Cornwall, at Huel 

 Sparnon, arborescent and reticulated on 

 Quartz, and at the following mines : Dol- 

 coath, St. Austell Consols, Huel Herland, 

 Wherr}', Botallack, &c. Force Craig, near 

 Keswick, in Cumberland. — Scotch. Esso- 

 chossan Glen, Argyllshire. Breeton, near 

 Alva, in Stirlingshire. — Foreign. Tunaberg, 

 in Sweden. Freiberg, Annaberg, and par- 

 ticularly at Schneeberg, in Saxony. Joa- 

 chimsthal, in Bohemia. Andreasberg, in the 

 Harz. Riechelsdorf, in Hesse. Allemont, 

 in Dauphiny. Chatham, in Connecticut, 

 U. S. (^Chathamite). 



Brit. Mus., Case 4. 



M P. G. Principal Floor, Wall-case 9 

 (British). 



Under the name Smaltine are, strictly 

 speaking, included onlj^ the Cobaltic va- 

 rieties represented by the formula CoAs = 

 cobalt 28*2, aisenic 71*8 = 100. The nickel 

 variety, represented by the formula NiAs, 

 or nickel 28*3, arsenic 91-7, is called Chlo- 

 anthite. These varieties merge into one 

 another by gradual transitions. 



Smaltine is one of the most important 

 ores of Cobalt, being (with Cobaltine) that 

 from which the greater part of the Smalts 



