194 JACINTH. 



Fractare imperfect-conclioidal. H. 1. S.G. 

 1-008. 



At 169° F. becomes soft, retains its tena- 

 city at 212° F., whence the name '!«?, glue, 

 and ^!^'», to dissolve. 



Locality. A bed of bituminous coal at 

 Oberhart, near Gloggnitz, in Austria. 



Brit. Mus., Case 60. 



J. 



Jacin^th, or Jacynth, See Hyacinth. 

 Jade, Jade Ascien, Jade de la Chine, 

 Jade Nephiutique, Haiiy. See Nephrite. 

 Jade he Saussukb. | See 



Jade Tenace, Haiiy. j SaussuPvIte. 

 The French word jade is supposed by 

 Estner to be derived from the name lyida, 

 by whicli it is called in India. 

 Jais, French. See Jet. 

 Jalpaite, Breithaupt. Cubical. Colour 

 blackish lead-grey. S.G. 6-877 to 6-89. 



Comp, Cupriferous Silver Glance, repre- 

 sented by the formula (|Ag + 4Cu) S. 

 Analysis, by R. Richter ; 



Sulphur .... 14-36 

 Silver ..... 71-51 

 Copper ..... 13-12 

 Iron ..... 0-79 



100-00 

 Name. From Jalpa, its locality in Mexico. 

 Jamesonite, Dufrenoy, Greg ^ Lettsnm, 

 Haidinger, Phillips. Rhombic: primary 

 form a right rhombic prism. Occurs in 

 acicular crystals, or in fibrous masses, with a 

 columnar structure, and composed of straight 

 and parallel or divergent particles. Colour 

 and streak steel-grev. Lustre metalHc. 

 Opaque. Sectile. H. 2 to 2-5. S.G. 5-5 to 58. 



Fig. 245. 



Co7np. Sulphantimonite of lead, or 3Pb 



S, 2Sb'8, or Pb^, Sb2 = sulphur 20-2, anti- 

 mony 36-2, lead 43-6=100. 

 Analysis, from Cornwall, by H. Rose 



Sulphur 

 Antimony 

 Lead . 

 Iron 

 Copper . 



22-15 



34-40 



40-75 



2-30 



0-13 



99-73 



JARGON. 



BE in an open tube affords dense white 

 fumes of oxide of antimony. On charcoal, 

 decrepitates, fuses readily, and almost en- 

 tirely passes off in fumes, depositing a subli- 

 mate of the oxide of lead and antimony, 

 and leaving a slag containing iron. 

 Soluble in warm muriatic acid. 

 Localities.— English. Cornwall ; near Pad- 

 stow ; Huel Lee, near Calstock ; Port Quin 

 Cliffs and Trevinnock, near Endellion ; Port 

 Isaac, Pendogget. — Foreign. Siberia. Hun- 

 gary, disseminated in Calc Spar. Spain. 

 Brazil, &c. 



Name. After Professor Jameson, of Edin- 

 burgh. 



The perfect cleavage at right angles to 

 the axis of the prism is very characteristic 

 of Jamesonite, and is sufficient to distin- 

 guish it from those minerals which it may 

 resemble in other respects. 

 Brit. Mus., Case 11. 



3L P. G. Principal Floor, Wall-case 14 

 (British). 



Janolite, La Metherie. See Axinite. 

 Jargionite *, C. Bechi. A variety of Ga- 

 lena, from Tuscany, containing antimony 

 and silver. It is near the Bleischweif of the 

 Germans, and may be identical with Stein- 

 mannite, like which it occurs crystallized 

 in octahedrons. 



Analysis, from Argentiera, in the Val di 

 Castello, by Bechi : 



Sulphur .... 15-62 



Lead 72-90 



Antimony .... 5-77 

 Iron ..... 1-77 



Copper l-ll 



Zinc 1-33 



Silver 0-72 



Jargon, or Jaegoon. 



98-22 

 The name given 



Fig. 246. 



^^ 



to a Cingalese variety of Zircon. It is seldom 

 perfectly transparent, and is either colour- 

 less or grey, with tinges of green, blue, red, 



* Tiie first notice of this mineral appeared in 

 the American Journal of Science and Arts ([2] 

 vol. xvi. p. 60), spelt as above. Most likely (as 

 suggested by Mr. Warington Smyth), the name 

 ought to be Targionite (after Targioni Tczzetti, 

 the Italian geologist), in which case the error pro- 

 bably originated in a mistake on the part of the 

 printer, in misreading J in the MS. for T. , 



