LEAD-EARTH. 

 Comp. Phosphate of alumina and mag- 

 nesia, or 2(Mg, Fe)3 P + Ais ps + oH =phos- 



Fig. 254. 



Fig. 255. 



phoric acid 43-88, alumina 31*77, protoxide 



of iron 7-10, magnesia 11*87, water 7-12 = 



100. {Smith §■ Brush.) 

 Analysis, from the Fischbach Alp in the 



circle of Gratz, by Rammelsberg. S.G. 3-11 : 

 Phosphoric acid . . . 43-84: 

 Alumina .... 33'09 

 Magnesia .... 9-00 

 Protoxide of iron . . . 6'69 



Lime 1'44 



Water ..... 5-94 



100-00 

 BB swells up, becomes coloui-less, and 

 falls to pieces, but does not fuse ; colours the 

 flame pale bluish-green. 



Not affected by acids till after ignition, 

 when it is almost wholly soluble. 



Localities. In narrow veins traversing 

 clay-slate, in the torrent beds of Schladming 

 and Radelgraben, near Werfen, in Salzburg, 

 with Spathic Iron. Vorau ( Voraulite), in 

 Styria, with Quartz ; also near Gratz and 

 Krieglach. Tijuco, Minas Geraes, Brazil. 

 Lincoln co.. North Carolina, U.S., in beauti- 

 fal sky-blue crystals. 



Name. From" an Arabic word azul, heaven, 

 because of its blue colour. 



Lazulite is distinguished from Lapis Lazuli 

 by never being accompanied by Iron Pyrites. 



Brit. Mus., Case 57. 



Lead-earth. Earthy carbonate of lead. 



Lead-glance, Jameson. Sulphide of lead. 

 See Galena. 



Lead-ochre. See Plumbic Ochre. 



Lead-spar. See Cerusite. 



Lead-vitriol, Jameson. See Anglesite. 



Leadhillite, Beudant. Leadhillit, 

 Haidinger, v. Kohell. Rhombic : primary form 

 a right rhombic prism. Colour yellowish, 

 or greenish-white, to grey, green, yellow, 

 or brown. Lustre resinous, inclining to ada- 



rr\ 



Fig. 256. Fig. 257. 



mantine; pearly on the cleavage-plane. 

 Transparent to translucent. Streak white. 



LECONTITE. 211 



Rather brittle. Fracture obscure -conchoidal 

 H. 2-5. S.G. 6-2 to 6-5. 



Comp. Sulphate and carbonate of lead- 

 oxide, Pb S + 3Pb C = sulphate of lead 27-44, 

 carbonate of lead 72-56 = 100. 

 Analysis, by Thomson : 



Sulphate of lead , . . 27-43 

 Carbonate of lead . . 72-57 



10000 

 BB intumesces, and becomes yellow, but 

 turns white again on cooling. On charcoal 

 easily reduced to metallic lead. 



Effervesces briskly in nitric acid, leaving 

 a white residue of oxide of lead. 



Localities. — British. Leadhills, in Lanark- 

 shire, with other ores of lead. Red Gill, 

 Cumberland, in Quartz. — /brez«7n. The 

 Island of Serpho, irt the Grecian Archi- 

 pelago. Grenada, in Spain. 



The pearly lustre of the cleavage face is 

 very characteristic of Leadhillite. 



Brit. Mus., Case 55. 



LEBER-BLENDE,5m^AaMjo?. Is Considered 

 by Berzelius to be ordinai-y zinc-blende, 

 rendered impure by a mineral resin, or some 

 other mineral containing carbon. 



Lebererz, Werner. See Hepatic Cin- 

 nabar. 



Leberkies. Hepatic Pyrites (3Iarcasite). 



Lecontite, if. J. Taxjlor. Occurs in 

 rhombic crystals (right rhombic prisms), 

 varying much in size, some being an inch 

 in length, and narrow prisms, while others 

 are short, not exceeding the sixteenth of an 

 inch in length, and quite broad. It is co- 

 lourless and clear when free from the organic 

 matter which covers it externally, and has 

 a saline and rather bitter taste. H. 2 to 2'5. 



Comp. Sulphate of soda and ammonia, or 



(Na + NHN40) S + 2H. 



Analysis, by IV. J. Taylor : 

 Ammonia .... 12-94 



Potash 2-67 



Soda 17-56 



Sulphuric acid . . . 44-97 



Water 19.45 



Organic residue . . . 2-30 

 Inorganic do. . . . Q-ll 

 Phosphoric acid . . . trace 



100-00 

 It is named after Dr. John Le Conte, by 

 whom it was discovered in the cave of Las 

 Piedras, in the vicinity of Comayaga, in 

 Honduras, imbedded in a black matrix re- 

 sembling bitumen in appearance, which Dr. 

 Le Conte considers to be the decomposed 



