308 PYROPE. 



Analysis, from Zschopau, by Wohler : 



Oxide of lead . . . 82-29 



Phosphoric acid . . . 15-73 



Chlorine . . . - 1-98 



Peroxide of iron . . . trace 



100-00 

 BB fuses easily; on cooling, solidifies 

 ■with vivid incandescence to an angular 

 crystalline mass. On charcoal, with car- 

 bonate of soda, yields metallic lead. The 

 arsenical ores also fuse on charcoal, and 

 yield metallic lead. 



Soluble in nitric acid, giving a turbidity 

 •with nitrate of silver. 



Localities. — English. Cornwall; at Huel 

 Penrose, Huel Golden, Huel Alfred, Pen- 

 berthy Croft Mine. Beeralston, Devonshire. 

 Derbyshire; Bonsall Moor, Brassington, 

 and near Wirksworth. Cumberland ; Mexico 

 Mine, Driggeth Mines, Brand ygill. — Scotch. 

 Strontian Mine, Argyleshire. Leadhills, 

 coloured red and orange by oxide of chrome. 

 — Irish. Glenmalure, co. Wicklow. Lord 

 Londonderry's Park, co. Derry, on ochreous 

 sandstone. — Foreign. Zschopau and other 

 places m Saxony. Przibram, Mies, and 

 Bleistadt, in Bohemia. Szaszka, in the 

 Bannat. Clausthal, in the Harz. Poul- 

 laouen, in Brittany. Beresowsk, in Siberia. 

 Mexico. 



Name. From tJ^s, Jire, and /M>^(p->i, form ; 

 in allusion to the crj-stalline form assumed 

 in cooling by the fused globule BB. 



Brit. Mus., Case 57a. 



M.P.G. Principal Floor, Wall-cases 45 

 (British); 21 (Foreign). For varieties, see 



MiESITE, NUSSIERITE, PoLYSPH^RITE. 



Pyromorphite is now utilised as an ore 

 of lead, by careful roasting with charcoal. 



Pyrope, Karsten, Phillips. A dark-red 

 variety of Iron-Garnet, rarely found crys- 

 tallized, but generally in rounded or angular 

 grains, loose or imbedded. Transparent or 

 translucent. Lustre vitreous. Fracture con- 

 choidal. H. 7-5. S.G. 3-69 to 3-8. 



Comp. (R + it)Si. 





Analysis, from Bohemia 



by Klaproth : 



Silica . 



. 40-00 



Alumina 



. . 28-50 



Peroxide of iron . 



. 16-50 



Peroxide of manganese . 0-25 



Chromic acid 



. 2-00 



Magnesia 



. . 10-00 



Lime . 



. 3-50 



100-75 



PYROPHYLLITE. 



BB fuses with difficulty to a black glass : 

 with borax gives an emerald-green globule. 

 Brit. Mus., Case 36. 



This variety of Precious Garnet, which is 

 of a full crimson-rad colour, approaching to 

 that of a ripe mulberry, is sometimes also 

 called Fire-Garnet, from the resemblance of 

 its hue, when held between the eye and the 

 sun, to that of a burning coal ; hence the 

 name, derived from ■^v^, fire, and eW<?, ap- 

 pearance. For the same reason, the ancients 

 called it «v6««|, and also Carbuncle. The 

 Carbunculus Garamanticus, orGaramantine 

 Carbuncle, possessed this property in the 

 greatest degree, and is the true Garnet of 

 the moderns. 



When perfect and of large size, this stone 

 constitutes a valuable gem. The best way 

 of cutting it is en cabochon, with one or 

 two rows of small facets round the girdle of, 

 the stone. When cut in steps, the colour is 

 apt to appear more or less black ; but when 

 cut en cabochon, the point on which the 

 light falls displays a brilliant fire-red. 



The ancients used the carbuncle for en- 

 graving seals on, and prized it so highly, 

 that a very small stone was valued at 40 

 Aurei (£42 5.s-.) They obtained it from 

 Carthage and Massilia. ' At the present day 

 Pyrope is found in Ceylon in alluvial de- 

 posits, accompanied by Hyacinth and Sap- 

 phire ; In serpentine at Zoblitz in Saxony, 

 and on the mountains on the south side of 

 Bohemia. 



Pyrope may be distinguished from Corun- 

 dum or Spinel by the greater dulness of its 

 colour, and b}' inferior hardness. 



Pyrophane, Von Born. Hydrophane im- 

 mersed in melted Avax, by absorbing which 

 it is rendered transparent. Opal impreg- 

 nated with wax in a similar manner becomes 

 opaque on cooling. 



Pyrophane. A variety of Semi -Opal, 

 so called (from ^v^, fire, and (Pxivm, to appear) 

 because when heated in a spoon it becomes 

 transparent, but returns to its opaque state 

 when cold. It is said that some Pyro- 

 phanes are found in Armenia, which are 

 transparent while exposed to the sun, and 

 opaque at night. — Kirwan, Min. vol. i. p. 291. 



Pyrophyllite, Hermann. Foliated like 

 Talc ; often in fibrous radiated masses, and 

 small elongated prisms. Colour white or 

 pale green. Subtransparent, or transparent 

 and flexible in thin laminae. Lustre pearly. 

 Sectile. H. 1. S.G. 27 to 2-8. 



Comp. A12 Si5 + 2H = silica 65-2, alumina 

 29-6, water 5-2 = 100. 



