MOCK LEAD. 

 31. P. G. Horse-shoe Case, No. 561. | 

 Mock Lead. A name formerly given by 

 Cornish miners to Blende. 

 MoDUMiTE, Nicoh See Skutterudite. 

 MoEi.LE DE Pierre, Brochant. See 



LiTHOMARGE. 



MoFFRASiTE, Leymerie. A kind of Blei- 

 neierite, composed of shelly masses form- 

 ing alternating bands, some of which are 

 coloured brownish -grey, others yellowish- 

 brown. Fracture vitreous, wnth a somewhat 

 brilliant lustre. H. 5-5, does not scratch 

 glass. S.G. of yellow 4-25, of brown 5-46. 



Comp. Antimonite of lead. 



BB on charcoal fuses, giving off white 

 fumes and yielding globules of lead. 



Dissolves in nitric acid. 



Locality. Zamora in Spain, forming a 

 strong vein. 



Name. After M. de Moflfrah, attache to 

 the French embassy in Madrid. 



MoHSiNE. The name given to Leuco- 

 pyrite by Chapman, in compliment to the 

 late Professor Mohs, Auiic Councillor, of 

 Vienna. 



MoHsiTE. Levy. A Titaniferous Iron 

 from Dauphine, named after the late 

 Professor Mohs, Aulic Councillor, of Vienna. 



Fig. 292. 



MoLOCHiTES, PUny. See Malachite. 



MoLYBD^NGLANZ, V. LeonJiard. See 

 Molybdenite. 



Molybdanit, Haid'mger. See Molyb- 

 denite. 



Molybdanochee, Karsten. See Molyb- 



DINE. 



Molybdansilber, Mohs. An argenti- 

 ferous variety of Tetradymite (Telku'ic Bis- 

 muth) from beutsch-Piisen, in Hungary. 



Analysis, by Werhle : 



Tellurium .... 29-74 



Bismuth . . . . 6Mo 



Silver 2-07 



Sulphur .... 2-33 



95-29 

 Moly'bdate of Iron. Occurs in sub- 

 fibrous or in tufted crystals of a deep yellow 

 colour ; also pulverulent ; near Nevada City, 

 California. 

 Molybdate of Lead, Phillips. See 



WULFENITE. 



MOLYBDENITE. 243 



MoLYBDENA, Jameson, ~\ q„^ t\t^^. 



Glance. j 



MOLYBDENA OCHRE, NicoL See MOLYB- 

 DINE. 



MolybdeNE Sulfure, Brochant, HaUy. 

 See Molybdenite. 



Molybdenite, Haidinger, Beudant, Ni- 

 col. Hexagonal. Occurs in flat hexagonal 

 tables, with a cleavage parallel with their 

 terminal planes : generally massive with a 

 foliated structure, or iij scales. Colour 

 closely resembling that of fresh-cut metallic 

 lead. Lustre metallic. Opaque. Laminae 

 highly flexible, but not elastic. Streak 

 like colour, inclining to greenish. Leaves a 

 metallic-grey trace on paper, a greenish 

 streak on porcelain. Unctuous to the touch. 

 Yields to the nail. H. 1 to 1-5. S.G. 4-44 

 to 4-8. 



Cojnp. Bisulphide of Molybdenum, or 

 Mo, S2=: molybdenum 60, sulphur 40 = 100. 



BB on charcoal infusible; gives off sul- 

 phurous acid, covering the charcoal with a 

 yellowish-white incrustation. On platinum 

 wire colours the outer flame green. 



Dissolves in boiling sulphuric acid with, 

 evolution of sulphurous acid, and forms a 

 blue solution. 



Localities. — English. Cornwall ; Gwinear 

 and Gwennap, in Chlorite ; in old heaps at 

 Huel Gorland and Huel Unity; Huel 

 Friendship, Huel Mary, Drakewalls Mine. 

 Cumberland : near the source of the Caldew, 

 in granite; Caldbeck Fell. — Scotch. Mount 

 Coryby, at the head of Loch Creran, in 

 Argyleshire. Perthshire. At Tomnadashan, 

 on the S. side of Loch Tay, in abundance, 

 with Copper-Glance and Molybdic Ochre in 

 a dyke of syenite. — Foreign. Greenland. 

 Arendal in Norway. Numedahl in Sweden, 

 in hexagonal prisms. Saxony and Bohemia 

 with tin. Silesia in granite. Chessy in France, 

 in syenite. Near Mont Blanc, in grey gra- 

 nite. Haddam, Connecticut; Westmore- 

 land, New Hampshire; Chester, Penns}^- 

 vania, U.S. Peru. Brazil. 



Name. From f^oXiS^aiva,^ a mass of lead. 



Brit. Mus., Case 12. 



3L P. G. Principal Floor, Wall-case 13 

 (British) ; 20 and 40 (Foreign). 



Molybdenite is generally found imbedded 

 in or disseminated through granite, gneiss, 

 zircon-syenite, and other crystalline rocks. 

 It is distinguished from Graphite by higher 

 specific gravity, difference of streak, lustre 

 and fracture, and behaviour before the blow- 

 pipe. 



R 2 



