240 MIKROKLIN. 



Analysis, by Richard Muller : 



Silver 70-28 



Bromine .... 12o5 

 Chlorine .... 17-37 



100-00 

 Locality. Copiapo, in Chili, in a yellow- 

 ish - red compact limestone, with Native 

 Silver. 



MiKROKLiN, Breithaupt. See MiCRO- 



CLINE. 



Milch Quarz, Werner; Milk Quartz, 

 Phillips, Jameson. Is one of the vitreous 

 varieties of Quartz. It occurs massive, of 

 a milk-white colour, chiefly in Greenland. 

 When, as is sometimes the case, it has a 

 greasy lustre, it is called Greasy Quartz. 

 When cut and polished it opalesces into 

 wine-yellow. 

 Brit. Mus., Case 21. 



MiLLERiTE, Haidinger. Hexagonal. In 

 delicate, capillary, six-sided prisms, and 

 sometimes in diverging filaments. Colour 

 brass-yellow, inclining to bronze-yellow, 

 with a grey or iridescent tarnish. Lustre 

 metallic. Opaque. Streak bright. Brittle. 

 H. 3 to 3-5. S.G. 5 278. 



Comp. Sulphide of nickel, or Ni. S = 

 nickel 64-9, sulphur 35-1 = 100. 



Analysis, from Kamsdorf, by Rammels- 

 herg : 



Nickel 61-34 



Sulphur .... 35-79 



Iron 1-73 



Copper 1-14 



100-00 



BB on charcoal gives off sulphurous acid, 

 and fuses to a coagulated, ductile, mag- 

 netic mass of nickel (Berzelius) ; a black 

 bead (Kobell). 



Dissolves with difficulty in nitric acid, 

 easily in aqua-regia. 



Localities. — English. Ebbw Vale, Nant- 

 y-glo, and Mertiiyr-Tydvil, Glamorgan- 

 shire, South Wales, in nodules of Clay Iron- 

 stone. Devon ; near Ilfracombe, and at 

 Combe ]Martin. Cornwall ; at Fowey Con- 

 sols, Huel Chance and Pengelly M^ine. — 

 Foreign. Jolianngeorgenstadt, in Saxony. 

 Joachimsthal, in Bohemia. Andreasberg, in 

 the Harz. Sterling Mine, Antwerp. New 

 York, U. S. 



Name. After W. H. Miller, Professor of 

 Mineralogy in the University of Cambridge. 



Brit. Mus., Case 6. 



M. P. G. Principal Floor, Wall-case 9, 

 Nos. 475, 476 ^British). 



MiLoscHiNE, Herder. A chromiferous 



MIMETENE. 

 clay, of the same nature as Walchonskoite. 

 Occurs in soft amorphous masses, of an 

 indigo - blue to celandine - green colour. 

 Translucent at the edges. Adheres to the 

 tongue. Fracture conchoidal or earthy. H. 2. 

 S.G. 2-031. 



Comp. Hydrated silicate of alumina, or 



(AI, -er) Si + 3H. 



Analysis, by Kersten : 

 Alumina 



Silica .... 

 Oxide of chrome . 

 Lime .... 

 Magnesia 

 Water . . . , 



45-01 



27-50 



361 



0-30 



0-20 



23-30 



99-92 



BB infusible; decrepitates and falls to 

 pieces in water. 



OnW partially soluble in muriatic acid. 



Locality. Rudniak, in Servia, associated 

 with Quartz and Brown Iron-ore. 



Name. After Milosch Obrenowitsch, 

 Prince of Servia. 



MiMETENE, Dana. Mimetese, Beudant. 

 MiAiETEsiTE, Breithaupt, Nicol. Mimetite. 

 Hexagonal : occurs in regular six - sided 

 prisms, either perfect or with the terminal 

 edges replaced ; also fibrous and mammil- 

 lary. Cleavage parallel to the planes of the 

 prism, indistinct. Isomorphous with Pyro~ 

 morphite. Colour various tints of yellow, 

 passing into brown. Lustre resinous. Trans- 

 lucent. Streak white, or nearly so. Sectile. 

 Brittle. Fracture imperfect-conchoidal, or 

 uneven. H. 3-5 to 4. S.G. 7-19 to 7-25. 



Fig. 290. 



Coinp. Pb CI + 3Pb 



Analysis, from Johanngeorgenstadt, by 

 Woliler : 



Arseniate of lead . . . 82*74 

 Chloride of lead . . . 9-60 

 Phosphate of lead . . 7*50 



99-84 

 BB on charcoal emits arsenical vapours, 



fuses with difficulty, and yields a globule of 



lead. 



Dissolves readily in nitric acid, especially 



if heated. Gives a precipitate of lead from 



the solution on a zinc bar. 

 Localities. •— English. Cornwall, Huel 



