32 PHYSIOGRAPHY. 



Mascagnine Melaconite. 



1. It is, apparently, a pure sulphate of ammonia ; and is found in ef- 

 florescences, upon recent lava, at Etna and Vesuvius ; upon decomposed 

 lavas of Puzzuolo, in the coal measures of Aubin and Aveyron, on the 

 surface of sandy plains nearTurin, and dissolved in the lakes of Tuscany. 



MEERSCHAUM. (See Mctgnesite.) 



MEIONITE. (See Scapolite.) 

 MELACONITE. Cupreous Lusine-Ore. 



Massive ; composition impalpable ; earthy and pulveru- 

 lent. 



1. Fusible before the blow-pipe into a black scoria, and yielding glob- 

 ules of copper in the reduction flame- It is soluble in nitric acid, with- 

 out the disengagement of gas. According to BEUDANT, it consists of 



Oxygen - - - - - 20-17 



Copper 79-83 



It often contains the hydrated oxides of iron and manganese. 



2. It occurs in all copper mines, and is probably derived from the de- 

 composition of Copper Pyrites and Blue Malachite. That which is de- 

 rived from the decomposition of the latter species, is nearly pure. 



3. The most remarkable localities are Chessy near Lyons, Rhein- 

 breitbach on the Rhine, Lauterbach and Zellerfeld in the Hartz, Kup- 

 ferberg in Silesia, Hungary, Bannat and Cornwall.. 



MELANITE. (See Garnet.) 

 MELANOCHROITE. 



In rhombic prisms, having two faces enlarged, so. as to impart 

 to the crystals a tabular shape. 



Lustre resinous, dull. Translucent on the edges, to opake. 

 Color hyacinth-red, to orange-red. Powder brick-red. Sp.gr. 

 = 5-75. 



Compound Varieties. Massive. Composition impalpable. 

 1. Before the blow-pipe, it melts easily into a brown mass, -which, on 

 cooling, assumes a crystalline structure. 



2. Analysis. 



By HERMANN. 



Oikleoflead .... 76-36 

 Chromic acid .... 23-64 



