18 ANHYDROUS SULPHATES. 



gravitj''. By absorbing water, which it does 

 very slowh', it becomes changed to Gypsum. 

 At Bex extensive beds are altered in this 

 manner, but by digging to a depth of 60 to 

 100 feet, the Anhydrite is found unaltered. 

 See also Gekrosstein, Muriacite, Vulpi- 



NITE. 



Name. From a, priv., and vT,u^, water. 



Brit. Mus., Case 54. 



Anhydrous Binoxide of Manganese, 

 Turner. See Pyrolusite. 



Anhydrous Scolezite : anhydrous lime- 

 Labradorite from Pargas, in Finland. 



Anhydrous Silicate of Iron, Phillips, 

 Tho7nson. See Fayalite. 



Anhydrous Silicate of Manganese, 

 See Tephronite. 



Anhydrous Silicate of Zinc. See 

 Hebetine, Troostite, Willelmine, 



WiLLEMITE, WiLLIAMSlTE. 



Anhydrous Sulphate of Alumina. 

 See Thenardite. 



Anhydrous Sulphate of Lime. See 

 Anhydrite. 



Anhydrous Sulphate of Soda and 

 Lime, Cleaveland. See Glauberite. 



Ankerite, Dana, Nicol, FhiUips, Hai- 

 dinger, Greg §" Lettsom. A crystallized va- 

 riety of Dolomite, containing a large pro- 

 portion of iron. 



Hexagonal. Yellowish, or reddish-white ; 

 becoming brown on exposure. Translucent 

 at the edges. Lustre vitreous, inclining to 

 pearl V. Brittle. Fracture uneven. 11. 

 3-5 to 4. S.G. 2-95 to 3-1. 



Comp. Ca C + (Fe, Mg, Mn) C. 



Analysis by Berthier, from GoUrath : 

 Carbonate of lime . . 51-1 

 Carbonate of iron . . . 20-0 

 Carbonate of magnesia . 25-7 

 Carbonate of manganese , 3*0 



998 

 BB becomes black and magnetic; with 

 borax gives the colour of iron ; with soda 

 gives indications of manganese. 



Dissolves with effervescence in nitric acid. 



Localities. Near Torness, in the Orkneys, 

 massive and in curved crj^stals, in amygda- 

 loid ; Golrath, Eisenerz, and the Nieder Alp 

 in Styria, with Siderite ; Eathhausberg, in 

 the valley of Gastein, in Salzburg, in mica- 

 slate. See also Rohwand. 



Name. After Prof. Anker, of Gratz. 



Brit. Mus., Case 47. 



Annabergite, Dana, Haidinger. Ob- 

 lique. Occurs in capillary crystals of a line 

 apple-green colour, adhering to, or coating. 

 Arsenical Nickel, of the decomposition of 



ANORTHITE. 



which it is a result. It is soft, and has a 

 greenish-white streak, and an uneven or 

 earthy fracture. H 2 5 to 3. G. 3-078 to 

 3-131. 



Comp. Ni5 As + 8H = oxide of nickel 

 37-59, arsenic acid 38-41, water 24-00 = 

 100. 



Analysis by Kersten : 

 Arsenic acid . . . 38-30 

 Oxide of nickel . . . 36-20 

 Oxide of cobalt . . .1-53 

 Water .... 23-91 

 Protoxide of iron . . trace 



99-94 

 BB on charcoal, gives out an odour of 

 arsenic, and, in the inner flame, fuses to a 

 metallic globule. 



Dissolves in nitric acid. 



Annabergite occurs, with White Nickel, at 

 Allemont, in Dauphiny, at Annaberg*, and 

 elsewhere. » 



31. P. G. Principal Floor, Wall-case 20. 



Annivite, Dufrenoy. A minei'al analo- 

 gous to Grey Copper, and according to 

 Kenngott, an impure variety of that ore. 

 It is found in the valley of Annivier with 

 Copper Pyrites. 



Anorthite, Rose, Dana. Anorthic. Pri- 

 mary form an oblique rhombic prism. Oc- 

 curs in white translucent or transparent 

 crystals, with a vitreous lustre inclining 

 to pearly on the planes of cleavage. Streak 

 white. 'Fracture conchoidal. H. 6 to 7. 

 S.G. 2-66 to 2-78. 



Fig. 21. 



Comp. Ca3 Si + 3 Al Si or like Scapolite, 

 except that small portions of the lime are 

 replaced by magnesia, potash, and soda. 



Analysis by Abich, from Somma : 



Silica 4412 



Alumina .... 35-12 

 Peroxide of iron. . . 0-70 



Lime 19-02 



Magnesia .... 0*56 



Soda 0-27 



Potash . . . .0-25 



100-04 



* Whence the name Annabergite. 



