23: 



MEIOXITE. 



resemblance to Embolite in physical cha- 

 racters. Crystalline form cubic. Colour 

 siskin- to pistachio -green, changing on ex- 

 posure to the light to blackish-grey. Lustre 

 adamantine. Streak pale green. Slightly 

 malleable and sectile. Fracture conchoidal 

 and uneven. H. 2'75 to 3. S.G. 6-23 to 

 6-234. 



Comp. 4Ag CI + 5Ag Br. 

 Analysis, by T. Richter ; 



Silver 64-19 



Bromine .... 26-49 

 Chlorine .... 9-32 

 Iodine trace 



100-00 

 Locality. Copiapo in Chili ; in compact 

 limestone. 



Me'ionite, Haily. Pyramidal ; primary 

 form a right square prism. Generally oc- 

 <airs in small four- or eight-sided prisms 

 terminated by tetrahedral pyramids, the 

 edges or angles of Avhich are sometimes re- 

 placed. Colour whitish or greyish-white. 

 Lustre vitreous. Translucent to transparent. 

 Often traversed bv fissures internally. 

 Scratches glass. H. 5-5 to 6. S,G. 2-5 to 2-74. 



Comp. Ca3 Si + 2A1 Si = silica 42-1, alu- 

 n-iina 31-9, lime 26 = 100. 



Analysis, from Vesuvius, by Stromeyer: 



Silica 40-53 



Alumina . . . .32 73 



Lime 24-25 



Soda and potash . . .1-81 

 Peroxide of iron . . .0-18 



99-50 



BB swells up strongly, and fuses to a 

 blistered colourless glass. 



Perfectly decomposed by muriatic acid, 

 with the formation of a jelly. 



Locality. Monte Somma, near Vesuvius, 

 generally in geodes, or adhering to frag- 

 ments of granular limestone. 



Name. From ^-;7»v, hss, in consequence of 

 the pyramid with which the crystals are 

 usually terminated being less acute than in 

 Idocrase. 



Brit. Mus. Case 31. 



M.P. G. Upper Gallery, Table-case A in 

 recess 4, Nos. 100 to HI." 



Melaconise, Beudant. Melaconite, 

 Dana. Melakonite, Dufrenoy. An earthy 

 and impure black oxide of copper, i-esulting, 

 probably, from the decomposition of Erubes- 

 cite and other ores. Occurs in pseudo- 

 morphous cubic forms; also pulverulent 

 and earthy, and massive. Colour dark steel- 

 grey to black. Lustre sub-metallic. Opaque. 



MELANITE. 



Streak shining. Commonly friable and soi'- 

 ing the fingers. S.G. 5-2. 



Comp. -C-u = copper 79'85, oxygen 20*15 

 = 100. Often contains a large percentage 

 of oxide of manganese and of water. 



BB affords a globule of copper in the 

 inner flame. 



Localities. English. — Cornwall ; at Huel 

 Buller, Huel Trefusis, and other mines, in 

 gossan. Hay Gill and Roughten Gill, Cum- 

 berland. Great Orme's Head, Caernarvon- 

 shire, in limestone. Foreign. — Chessy near 

 Lyons. Siberia. Peru. Copper Harbour, 

 Keweenaw Point, Lake Superior, forming 

 a vein in conglomerate. 



Name. From M-iKag, black, and xova, powder. 



Brit. Mus., Case 17. 



M P. G. Principal Floor, Wall-Bases 1 

 (British); 15 and 17 (Foreign). 



Melanasphalt, Wetherill. The name 

 given to the Albert Coal of Nova Scotia, 

 which has the appearance, but not the fusi- 

 bility, of Asphaltum. It contains 58-8 to 

 61-6'7 per cent, of volatile matter, according 

 to Dr. Jackson. Dr. Wetherill states that 4 

 parts are soluble in ether and 30 in turpen- 

 tine. 



Analysis, by Dr. Wetherill : 



Carbon .... 82-670 

 Hydrogen .... 9-141 

 Oxygen, nitrogen . . 8*189 



100-000 



See Aebert Coal. 



Melanchlor, Fuchs. A blackish-green 

 variety of phosphate of ii'on, from Eaben- 

 stein, stated by Soemann to be a result of 

 the alteration of Triphyline. It contains, 

 besides impurities, about 3-87 per cent, of 

 protoxide of iron, 38-9 peroxide of iron, 25-5 

 to 30-3 phosphoric acid, and 9 to 10 of water. 

 S.G. 3-38. 



BB fuses readily into a black magnetic 

 globule. 



Readily soluble in warm muriatic acid. 



Name. From f^i>-cc?, black, and xXu^dsy 

 green, in allusion to its colour. 



Melanglanz. See Stephanite. 



IVIelanite, Jameson, Phillips. A variety 

 of Iron-limeGarnet, of a velvet-black co- 

 lour. Opaque. Occurs in rhombic dodeca- 



Fig. 2S4. 



hedrons, whose edges are replaced. Streak 

 grey. S.G. 3-7. 



