STANNOLITE. 



Stannolite (from stannum, tin, and 

 >-'^e=, stone) The name given by Necker 

 to Oxide of Tin or Tinstone. See'CASsixE- 



EITE. 



Stanzait. See Andalusite. 



Star Ruby. "j 



Star Sapphire, y See Asteria. 



Star Stone. J 



Stassfurthite, Rose. Under the micro- 

 scope appears to be formed of an aggrega- 

 tion of prismatic crj'stals, which have been 

 shown by analyses of Karsten and Chapman 

 to be identical in composition with Boracite. 

 According to the following analysis by 

 Heintz, by whom it has subsequently been 

 examined, its composition is represented by 



the formula 2(Mg3 i]4) + Mg CI H, or Bora- 

 cite with one atom of water. S.G. 2'94. 

 Analysis : 



Boracic acid . . .61 -22 



Magnesia .... 2o"74 

 Magnesium . . .2*84 



Chlorine .... 8-14 

 Peroxide of iron . . . 0'43 

 Water . . . .163 



100-00 

 BB more easily fusible than Boracite, 

 Slightly soluble in hot water. Dissolves 

 readily in warm concentrated muriatic acid. 

 Locality. Stassfurth, in Prussia. Liine- 

 burg, in Brunswick. 



Stauroi.ite, Kirwan, (from (TTctv^o;, a 

 cross, and ^'So;, stone.) See Harmotome. 



Staurolite, Karsten, Nieol, Phillips 

 Staurolith, IVerner. Staurotide, Dana, 

 Haiiy. Rhombic : primary form a right 

 rhombic prism. Occurs sometimes in rhom- 

 bic prisms, the acute edges of which are 

 frequently replaced, converting them into 

 six-sided prisms. The crystals are thick, 

 and often intersect and cross each other at 

 right angles, or at an angle of 120°; in 

 which case they are often rough and of a 

 dull brown colour; otherwise the colour 

 varies from a reddish-brown to a brownish - 

 black. Translucent to opaque. Lustre 

 vitreo-resinous. Streak white or greyish. 

 Fracture conchoidaL H. 7 to 7*5. S.G. 

 3-5 to 3-8. 



Fig. 410. 



Cb/np, (Al ¥q) Si, or silicate of alumina, 



STEATITE. 359 



with about one-third of the alumina re- 

 placed by peroxide of iron = silica 29 3, 

 alumina 53"5, peroxide of iron 17-2 = 100. 

 Analysis, from St. Gotthard, by Jacobson : 

 .... 29-13 



Silica 

 Alumina 

 Peroxide of iron 

 Magnesia 



52-01 



17-58 



1-28 



10000 



BB in a finely powdered state, fuses to a 

 black slag: in borax dissolves slowly, 

 forming a clear, dark green glass: with 

 carbonate of soda eflfervesces, and yields a 

 yellow slag. 



Not acted on by muriatic acid : partially 

 decomposed by sulphuric acid. 



Localities. — English. Cornwall and Devon - 

 shire, in clay-slate. — Scotch. Ardonald, 

 Aberdeenshire. Unst, in the Shetlands. — 

 Irish. Near Killiney, south of Dublin, at 

 the junction of mica-slate and granite. Glen 

 IMalure, co. Wicklow. — Foreign. St. Gotthard, 

 in Switzerland, in talc-slate, Jig. 409. 

 Greiner Mountain, in the Tyrol. The Ural. 

 Bohemia. Brittany. St. Jago de Compos- 

 tella, in Spain. Oporto, in Portugal. United 

 States. 



Name. From a-Totv^o?, a cross, and A;U,-, 

 stone. 



Staurolite generally occurs imbedded in 

 mica-, talc-, and clay-slate, sometimes in 

 gneiss. 



Brit. Mus., Case 31. 



31. P. G. Upper Gallery, Wall-case 45, 

 Nos. 102 to 104, 138 to 140. 



Staurotypous Kouphone Spar, Mohs. 

 See Phillipsite. 



Steatite, Phillips. A massive variety of 

 Talc, of various tints of white, grey, yellow, 

 green and red. It has generally a soft and 

 unctuous feel, like that of soap, and yields 

 to the nail, but does not adhere to the 

 tongue. Slightly translucent at the edges. 

 Fracture splintery,, but sometimes slaty. 

 H. 1 to 1-5. S.G. 2-65 to 2-8. 



Comp. Silicate of magnesia, or Mg^ Si^ 



+ 2H = silica 6214, magnesia 32-92, water 



4-94=1-00. 



Analysis, from Scotland, by Lychnell: 



Silica 64-53 



Magnesia .... 27'70 



Protoxide of iron 



6-85 



99-08 

 BB fuses at the edges to a white enamel : 

 ignited with solution of cobalt, assumes a 

 pale red colour. 



AA 4 



