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IsTEPHT.LIXE. 359 Protoxide of manganese . r55 Magnesia 0'40 Lime 26-19 Soda 7-78 Water o-24 Is found in tabular and columnar crystals, and angular grains, in some islands in Langesund-Pjord, and in the island of Itodkindholmen near Fried richswarn in Norway. 202. NEPHELINE.—Nepheline ; Phillips, Hauy. Rhom- boedrischer Elain-Spath; Mohs. Nephelin; Hausmann, Hai- dinger. Rhombohedral. 100,111 =r 59° 10'. 0 in, a oil, b 211, x 120, x 131. ao 90° o' ad eo 0 bd 30 0 xo 44 3 eo 62 40 xd 40 41 zd 62 44 Combinations, oa, oax, oaxz, oabxz. feet. Fracture conchoidal...uneven translucent. Lustre vitreous. Surfaces of fracture, especially of the coloured varieties, resinous. Colourless, greenish-grey, flesh-red inclining to brown, blue inclining to green. Streak white. Brittle. 11 = 6-6...6-0. a = 2 4 68...2 , 64. Before the blowpipe nepheline melts with difficulty, elaeolite more readily, into a blebby glass. Is decomposed with great difficulty by salt of phosphorus. With solution of cobalt the melted edges become blue. A translucent splinter becomes opaque in nitric acid. In powder is completely decomposed by hydrochloric acid, forming a jelly of silica. R 4 Si s + 2APSi 3 , where it denotes Na, K, Ca. Analyses of the white varieties (nepheline), a from the Kat- zenbuekel by L. Gmelin, b from the Katzenbuckel by Scheerer, e, d, e from Monte Somma, all by Scheerer,/from Vesuvius by Arfvedson:— a b c d e f Silica 43'36 43-70 44’03 44'29 44'04 44’11 Alumina .... 33'49 32'31 33-28 33-04 34-06 33'73 no. 376. Cleavage. 0, a imper- Transparent... feebly
