248 MITSEXITE. 



ency and ability to withstand the effects of 

 fire, to form the fronts of stoves with plates 

 of Mica, by which means the peculiar ad- 

 vantage of the stove is in some degi-ee com- 

 bined with the cheerful appearance of an 

 open fire. 



Muscovite was used by the ancients for 

 protecting plants against" the cold; and in 

 this way, it is stated by Columella, the table 

 of Tiberius was supplied with cucumbers 

 almost all the year round. 



MtJSENiTE. A name for Siegenite, given 

 from the locality Mlisen, where it occurs. 



MusHET Stone. See Black- band. 



MussiTE, A greyish-green variety of 

 Diopside from the Mussa Alpe in Piedmont. 



Brit. Mus., Case 34. 



MussoNiTE, Dufrenoy. A name for 

 Parisite, after its locality, the Musso Valley. 



Myelin, Breithanpt. A variety of Kao- 

 lin of a yellowish or reddish colour, from 

 Rochlitz in Saxony. 



Analysis, by Kersten : 



Silica ..... 37-62 

 Alumina .... 60*50 

 Magnesia .... 0-82 

 Peroxide of manganese . 0*63 

 Peroxide of iron . . . trace 



99-57 

 Mysorine, Beudant. Massive, with a 

 pulverulent texture. Colour brownish-black, 

 when pure, but generally tinged with green 

 and red, from admixture Avith Malachite 

 and oxide of iron. Fracture small-conchoi- 

 dal. Soft. S.G. 2-62. 



Comp. Anhydrous carbonate of copper. 

 Analysis, by Thomson : 



Oxide of copper . . . 60"75 

 Carbonic acid . . . 16-70 

 Peroxide of iron (mechani- 



callv mixed) . . . 19'50 

 Silica" 2-10 



99-05 

 Locality. Mysore, in Hindostan, forming 

 beds in the older rocks. 



N. 



Nacrite, Thomson. Consists of minute 

 grains or scales, of a silvery-white or green- 

 ish colour, with a glimmering pearly lustre. 

 Friable and unctuous to the touch, like a 

 soft earthy Talc. Adheres to the fingers. 

 Gives an argillaceous odour when breathed 

 on. H. 0-5. S.G. 2-788. 



NAIL-HEADED COPPER-ORE. 



Comp. Anhydrous silicate of alumina. 

 Analysis, from Brunswick, U. S., by 



Thomson 

 Silica . 

 Alumina 

 Protoxide of iron 

 Water . 



. 64-44 



. 28-84 



. 4-43 



, 100 



98-71 



BB infusible. 



Localities. Piedmont. Freyberg, in 

 Saxony. Near Meronitz, in Bohemia. 



Name. Sp. nacar; It. naxhera; Fr. 

 nacre ; mother o' pearl. 



See also Talcite. 



Nadeleisenerz, Naumann. See Go- 



THITE. 



Nadelerz, Werner. Acicular Bismuth. 

 See AiKENiTE. 



Nadelstein, Werner. See Scolecite. 



Nagyagererz, Werner. Nagyagite, 

 Haidinger. Pyramidal : primary form a 

 right square prism. Occurs in small six- 

 sided tables, with a basal cleavage ; also 

 massive-granular, but generally foliated. 

 Colour and streak dark lead- grey. Lustre 



Fig. 299. 



metallic. Opaque. Soft and sectile. In thin 

 laminae highly flexible. H. 1 to 1-5. S.G. 

 6-68. 



Comp. Telluride of lead and gold ? 

 Analysis, by Klaproth : 



Lead 54-0 



Tellurium . . . .32-2 



Gold 9-0 



Copper . , . \ .1-3 



Silver 0-5 



Sulphur 3-0 



100-0 



BB fuses very readily, emitting a dense 

 vapour, colouring the iiame blue, and de- 

 positing a yellow film on the charcoal, and 

 yields a globule of gold, Avith a Tittle silver. 



Dissolves in nitric acid, leaving a residue 

 of sulphur. 



Localities. Nagyag and Offenbanya, in 

 Transylvania, in foliated masses and crys- 

 talline plates. 



Brit. Mus., Case 3. 



Nail-headed Copper-ore. The name 

 given in Cornwall to certain crystals of 

 Chalcosine, from their fanciful resemblance 

 to the heads of nails. This resemblance is 

 more striking when they form the termina- 

 tion to prismatic crystals, as is sometimes 



