358 SPONGIFORM QUARTZ. 



BB swells up, imparting at the same 

 time a slight and transient purple-red 

 colour to the flame, and fusing with tolerable 

 facility to a greyish-white glass, which is 

 nearly transparent. 



Is not acted on by acids. 



Localities. — Irish. Killiney, co. Dublin, 

 in long, bent prisms of a greenish-grey 

 colour in white granite. — Foreign. Island 

 of Uto, in Sweden, with Magnetic Iron Ore, 

 red Felspar, Quartz and Tourmaline. Near 

 Sterzing and Lisens, in the Tyrol. Sterling 

 and Norwich, Massachusetts; and other 

 places in the United States. 



Name. Fi'om a-^oltb;^ ash-coloured. 



Brit Mus., CaseSl, 



The Spodumene of Killiney is sometimes 

 employed for obtaining lithia. 



Spongiform Quartz. Quartz presenting 

 a porous spongiform appeai'ance. See Float- 

 stone. 



Spreustein. See Natrolite. 



It has been shown by Scheerer that only 

 the perfectly white specimens of this mineral 

 are free from mechanical mixture ; and the 

 colour of the red and brown varieties is 

 caused by the presence of mechanical im- 

 purities. 



Sprodglanzerz, Hausmann. Sprod- 

 GLASERz, Werner. Brittle Silver Ore. See 

 Stephanite. 



Sprudelstein. a stalactitic variety of 

 Aragonite, deposited from the Carlsbad 

 springs, and containing 0'69 per cent, of 

 fluoride of calcium, and a trace of arsenic. 



Spurious Coal. The name used by 

 Kirwan to denote those kinds of Coal which 

 contain a notable quantity (more than 25 

 per cent.) of stony matter. 



Stachelschweinstein, or Hedgehogstone. 

 A variety .of Brown Iron Ore, found inclosed 

 in Rock Crystal, on the Nake, at Oberstein 

 in Northern Germany. 



Stahlcobalt, or Ferrocobaltine. A 

 variety of Cobaltine from the Hamberg 

 mine, Siegen, in Westphalia, which has 

 three- fourths of the cobalt replaced by iron. 



Analysis, by Schnabel : 



Sulphur .... 19'98 

 Arsenic . . . .42-53 



Iron 25-98 



Cobalt ..... 8-67 

 Antimony . . . .2 84 



100-00 

 Stahlstein. See Chalybite. 

 Stalactite (from a-roiXxxTis, that which 



STANNITE. 

 drops); or Stalactitic Carbonate of 

 Lime, Phillips. A form of Calcareous Spar, 

 deposited in long mammillated and pendant 

 masses resembling icicles, on the roofs of 

 caverns and in fissures in limestone ro>.ks. 

 Water, charged with an excess of carbonic 

 acid, in percolating through rocks contain- 

 ing carbonate of lime, dissolves a certain 

 quantity of it, which it holds in solution, 

 and carries away, until by the evaporation 

 of the water, as it trickles from the roof of 

 the cavern, a portion of the lime is redepo- 

 sited in a solid form. The water which 

 drops from the stalactite, or from the roof of 

 the cavern, in a similar manner, leaves a 

 deposit of Calc Spar, called Stalagmite, 

 which sometimes forms a floor to the 

 cavern, and sometimes a boss or protube- 

 rance, which gradually increases in height 

 by repeated deposition of lime ; and in this 

 manner, b}^ the increase in length of the 

 Stalactite in a downward direction, and the 

 growth of the Stalagmite upwards, the 

 two frequently meet and become united 

 into one mass. By the long continued opera- 

 tion of this slow process, in course of time, 

 considerable masses of calcareous spar 

 are accumulated, which frequentl}' assume 

 very fantastic and beautiful shapes, and 

 sometimes fill up the entire cavity in the 

 rock. In this manner the beautiful kind of 

 Aragonite has been formed which is found 

 in Egypt and Ali^eria, called Oriental 

 Alabaster (which see). 



31. P. G. Horse-shoe Case, Nos. 406a, 

 409, 410, 428. Upper Gallery, Wall-case 

 40, Nos. 1 to 5, and 9 to 11. Table-case 

 B, in Recess 6, Nos. 215 to 219. 



Stalactites Panniformes. A name 

 sometimes used to denote those kinds of 

 Stalactite which are attached to the sides 

 of caves, and present the appearance of un- 

 dulating folds of drapery. 



Stalagmite, from c-mx«y^a, a drop. Sec 

 Stalactite. 



Stangenspath, Werner. Columnar 

 Heavy-spar, found in indistinct prismatic 

 pearly crystals, of a white or greenish coloui, 

 near "Freiberg in Saxony. 



Stangenstein. See Pycnite. 



Stannine, Beudant, Greg §■ Lettsom, 

 Haidinger. See Tin Pyrites. 



Stannite, Breithaupt. A mechanical 

 mixture of Quartz and Oxide of Tin, found 

 formerly at Huel Primrose, in Cornwall, 

 both massive and in the form of Quartz 

 crystals. It is of a greyish-white colour, 

 with little lustre, and a conchoidal fracture. 

 H. 6-5. S.G.3-5. 



