310 PYROSTIBITE. 



Peroxide of manganese . 24-26 



Lime 1-21 



Chlorine .... 3-77 

 Water .... undetermined 



100-57 



BB assumes a blackish- brown colour, 

 gives off vapours of water, muriatic acid, 

 and sesquichloride of iron, and fuses to a 

 black magnetic globule. 



Dissolves in nitric acid, with separation of 

 silica. 



Localities. Sweden : at N"ya Kopparberg 

 in Westmannland, and Bjelkeygrube, one of 

 the iron mines of Nordmark, near Phillip- 

 stadt, in Wermland. 



Name. From ^v^^Jire, and oV.W'-^, odour ; in 

 allusion to the smell given off when heated. 



Brit. Mus., Case 57b. 



Pyrostibite, Glocker. See Kermesite. 



Pyroxene, Haily. Oblique; primary 

 form an oblique rhombic prism. Generally 

 occurs in short, thick crystals, and often in 

 twins : also amorphous, coarsely laminar, 

 granular and fibrous. Colour various shades 

 of green, grey and black; but sometimes 

 colourless or even white. Transparent to 

 opaque. Lustre vitreous or inclining to 

 resinous. Streak white to grey. Brittle. 

 Fracture conchoidal to uneven. H, 5 to 6. 

 S.G. 3-23 to 3-5. 



CZ^ 



Fig 353. 



Fig. 354. 



Comp. Bisilicate of various bases, repre- 

 sented by the general formula (R ir) Si^ 

 {Dana), in which R may be Ca, Mg, Fe, 

 Mn. When R = (Ca Mg) the colour is 



white or pale green ; when R = (Ca, Fe) the 

 colour varies from green to black; and when 

 iron forms an abundant ingredient the 

 colour becomes very dark green or black. 

 In the aluminous species, which all contain 

 alkalies, a portion of the silica is replaced by 

 alumhia {Dana). 



BB the dark varieties, containing iron, 

 afford an iron reaction. The paler varieties 

 fuse with effervescence to a colourless glass, 

 and with borax yield a clear glass. 



Localities. — English. Teesdale, Durham, 

 in basalt. — Welsh. Anglesea, in trap dykes. 

 Caernarvon : near Bangor, in trap rock. Moel 



PYRRHITE. 



Siabod. Summit of Penmaen Mawr. — Scotch. 

 Islands of Canna, Mull, and Rum, Argyle- 

 shire; in basaltic rocks. Isle of Arran. 

 Isle of Skye. Long Row and Lion's 

 Haunch, Arthur's Seat, Edinburgh, in 

 basalt. Island of Tiree, in Limestone. Ful- 

 ford lime-quarry, near Raith, in Fifeshire. 

 Blaikie Heugh, five miles east of Hadding- 

 ton, in felstone porphyry. North Berwick. 

 — Irish. Antrim co., Portrush. Fairhead. 

 Culfeightown, Tor Head. Near Clogher, 

 Tyrone. Tullyreagh, in Derry. — Foreign. 

 Aussig and Toplitz, in Bohemia ; also at 

 Oberrochlitz (compact white). Greenland. 

 Arendal, in Norway. Hungary. Transyl- 

 vania. Hesse. Auvergne. Monte Rossi, on 

 Etna. Vesuvius. Stromboli. Teneriffe. 

 Bourbon. Hawaii, in basaltic lava. Laacher- 

 see, &c., on the Lower Rhine, in basaltic 

 lava of the extinct volcanos of the Eifel. 

 Ascension, in basaltic lava. White Island, 

 New Zealand. 



Name. From ^v^, fire, and |sv»?, a guest ; 

 meaning a guest in the domain of fire; in 

 allusion to its mode of occurrence, as though, 

 it had formed an original part of the lava in 

 which it is found, which had escaped fusion, 

 and was not, therefore, a result of crystal- 

 lization consequent on the cooling of the mass. 



Pvroxene is, according to Dana, isomor- 

 phous with Hornblende; and this opinion 

 has been confirmed by the late researches of 

 Rammelsberg, who also states that both 

 are bisilicates. It cUffers from Hornblende, 

 however, in containing a smaller quantity of 

 silica, in being less fusible, and in having a 

 higher specific gravity. 



For varieties of Pyroxene, see Algerine, 

 Augite, Baikalite, Cocoolite, Diofside, 

 Fassaite, Hedenbergite, Jeffersonite, 

 Malacolite, Sahlite. 



Brit. Mus., Case 34. 



3LP.G. Horse-shoe Case,Nos. 1035,1042. 



Pyroxene Ferro-Manganesien, Beu- 

 dant. See Pyrosmalite. 



Pyroxene Granuliforme, Haiiy. See 



COCCOLITE. 



Py'rrhite, G. Rose. Cubical. Occurs in 

 minute octahedrons. Colour orange-yellow. 

 Subtranslucent. Lustre vitreous. H. 6. 



Comp. Probably Columbate cf zirconia, 

 coloured with oxides of iron, uranium and 

 manganese. 



BB infusible. In small splinters blackens, 

 and colours the flame deep yellow. 



Locality. Alabaschka, near Mursinsk, 

 lining drusy felspar-cavities. The Azores. 



Name. From ■^^e.o?, yellow. 



Pyrrhosidekite, Hausmann. From 



