PEA-MIXERAL. 



Pea-Mineral. See Pisophalt. 



Peach. A name given by Cornish miners 

 to Chlorite. 



Pearl Kerate, Mohs. See Calomel 

 and Kerate. 



Pearl Mica, Jameson. See Margarite. 



Pearl Sinter. See Fiorite. 



Pearl Spar. The most common variety 

 of Bitter Spar. It comprises the rhombohe- 

 dral crystallizations of Dolomite with curved 

 faces and a shining, pearly lustre. Colour 

 ■white, grey, or yellowish. Translucent. 

 Yields to the knife. Harder than Calc Spar. 

 S.G. 2 5. 



Localities. — British. The lead mines of 

 the north of England. Alston in Cumber- 

 land. Derbyshire. Beeralston, Devonshire. 

 Cornwall. Leadhills and Charlestown, Scot- 

 land. — Foreign. Schemnitz in Hungary. 

 Kapnik in Transylvania. Freyberg in 

 Saxony. Traversella in Piedmont. Gap in 

 Prance, &c. 



Brit. Mus., Case 47. 



Pearl-stone, Jameson. See Perl- stein, 



Peastone. Is, strictly speaking, a rock 

 rather than a mineral. It resembles Oolite 

 in structure, but differs from it in the larger 

 size of the grains of which it is composed. 

 These consist of concentric masses of a 

 round or spherical shape, varying in size 

 from a pea to a nut, and are imbedded in 

 a calcareous cement. 



Brit. Mus , Case 46. 



Peat. See Lignite. 



Pech-blende, Werner. See Pitch- 

 blende. 



Pecheisenerz. See Gothite. 



Pechekz, Werner. See Pitchblende. 



Pech-kohle, Werner; or Pitchcoal. 

 See Jet. 



Pechkupfee, Hausmann. See Kup- 

 ferpecherz. 



Pechstein, Werner. See Pitchstone. 



Pechstein de Menil-Montant. a 

 name for Menilite, after that of the locality. 



Pechuran, Hausmann. See Pitch- 

 blende. 



Pechuran Htacinthe, Dufrenoy. See 



GUMMIERZ. 



Pectolite, Beudant, Dana. Peckto- 

 LlTE, Dufrenoy. Pectolith, v. Kohell. 

 Oblique ; primary form an oblique rhombic 

 prism, and isomorphous with Wollastonite. 

 Occurs in spheroidal masses composed of an 

 aggregation of acicular crystals, or of deli- 

 cate fibres arranged in 3, radiated or stellar 

 form. Colour white or greyish. Lustre of 

 crystals vitreous : of fibrous silky to dull. 

 Transparent when crystallized: when 

 fibrous translucent to opaque. Very tough. 



PEGMATOLITE. 275 



Fracture splintery. H. 4 to 4*5. S.G. 2-65 

 to 2-88. 



Fig. 323. 



Comp. Silicate of lime and soda, or 



(KNa)5Si4 + 4Ca3Si2 + 3H = silica 54-22, 

 lime 33-73, soda 9-30, water 2-74 = 100. 

 Analysis, from Ratho, by Heddle ; 



Silica 52-58 



Lime 33-75 



Soda 9-26 



Alumina .... 4-15 

 Water 2-80 



99-84 



BE gives out a few bubbles of gas, and 

 fuses readily to a white translucent glass. 



Small pieces placed in concentrated muri- 

 atic acid, after several days become dis- 

 integrated, and yield gelatinous silica. 



Localities. — Scotch. Ayrshire : on the 

 shore near Landelfoot in white, fibro-crys- 

 talline, translucent radiations ; Knockdo- 

 lian Hill. Eatho quarries near Edinburgh, 

 in large orbicular masses {RathoUte), in 

 greenstone. Castle Eock, Edinburgh. 

 Prince Charles' Cave, and Taliskar, in Sk^^e. 

 Corstorphine Hills, in greenstone. Kilsyth, 

 Stirlingshire {Soda Table- Spar). Kilpa- 

 trick ( Stellite). — Foreign. Monte Baldo in 

 the Southern Tyrol ; and Monte Monzoni in 

 the Fassa-thal, m large masses. Isle Royal, 

 Lake Superior, K America. 



Name. From «r,y,To?, put together, and xido?, 

 stone. 



Brit. Mus., Case 28. 



M. P. G. Horse-shoe Case, Nos. 1186, 

 1187. 



Peganite, Breithaupt. Occurs in thin 

 crusts or very small rhombic prisms, with 

 the acute lateral edges truncated. Colour 

 emerald-green to white. H. 3 to 4. S.G. 

 2-49 to 2-54. 



Comp. Fischerite - 2H, or AP P + 6H. 

 Locality. Strigis, near Freiberg, and 

 at Frankenberg in Saxony. 



Pegmatolite, Breithaupt. Occurs in 

 short thick (often macled) crystals, of much 

 greater width than length, implanted in 

 druses on Dolomite. Colour faint reddish- 

 or yellowish-white. 

 Analysis, by Erni : 



Silica .' . . . . 65-58 

 Alumina .... 18-45 



Soda 10-41 



t2 



