ANDREASBEEGOLITE- 



and Andesite) of South America. It is also 

 met with in the syenite of Alsace, in the 

 Vosges, and at Vapnefiord, Iceland, in 

 honev -yellow transparent crystals. 



Andreasbergolite : Andreolite, or 

 Aj^dreolithe, La 3fether/e, names for Har- 

 motome; after that of the place where it 

 was tirst discovered, Andreasberg (in the. 

 Harz) and X'Sc?, stone. 



Anglarite. a fibrous and compact va- 

 riety of phosphate of iron, of a grey col(;ur 

 incHning to blue. Translucent. 



Comp. Fe4p + 4H. 



Analysis by Berthier : 

 Phosphoric acid 

 Protoxide of iron . 

 Water . 



. 27-3 

 . 56-0 

 . 16-5 



99-8 

 BB fuses to a black globule. 



LocaliUj. Anglar (whence the name An- 

 glarite) in the Haute Vienne, France. 



Anglesine, Beudant; Anglesit, Hald- 

 inger, v. Kobell ; Anglesite, Bettdant : Greg 

 &,-" Lettsom, Nicol, Dana. Rhombic : is a 

 sulphate of lead, occurring in rhombic 

 prisms with dihedral terminations, but the 

 crystals, when short, assume the general 

 form of the octahedron. Colour white, grey, 

 or yellowish ; frequently tinged blue or 

 green by oxide of copper. Lustre adaman- 

 tine, inclining to resinous. Transparent, 

 opaque. Yerv brittle, and yields to the 

 nail. Fracture conchoidal. H. 3. S. G. 6 2 

 to 6-3. 



Fig. 17. 



Fig. 18. 



Comp. Pb S = sulphuric acid 26*4, oxide 

 of lead 78-6 = 100. 



Analysis by Klaproth, from Anglesea : 

 Oxide of lead . . . 71 

 Peroxide of iron . . .1-0 

 Sulphuric acid . . . 24-8 

 Water 2-0 



98-8 ■ 

 BB decrepitates and melts to a globule, 

 which becomes milk-white when cool : in 

 the inner flame effervesces and is soon re- 

 duced to the metallic state. 



This ore of lead is derived from the de- 

 composition of Galena, with which it gene- 

 rally occurs. 



ANHYDRITE. 17 



Localities. — Anglesite was first obsei-ved as 

 a distinct species at Pary's mine in Anglesea 

 (whence the name). It is found in brilliant 

 crystals at Rent Tor, near Wirksworth; 

 and in small yellow crystals at Crom- 

 ford in Derbyshire ; in Cumberland, at the 

 Mexico mine, near Hesket Newmarket (fig. 

 17.) In Scotland, large and beautiful crystals 

 were formerly found at Leadhills in Lanark- 

 shire, and atWanlock Head in Dumfriesshire, 

 sometimes two inches long and with perfect 

 terminations. Small but extremely perfect 

 transparent crystals have been brought 

 from Fondon, in Granada. 



Brit. Mus. Case 55, 



M.P.G. Principal Floor, Wall-case 44, 

 No. 72 (British). 



Anhydrite Dana, Greg §• Lettsom, Phil- 

 lips, Jameson, Nicol : Rhombic : occurs (but 

 rarely) crystallized in the form of a rectangu- 

 lar prism, of which the lateral edges are 

 sometimes, though rarely, replaced. Chiefly 

 in granular, or almost compact aggregates, 

 or with a columnar structure. Colour white, 

 sometimes tinged with grey, blue, violet, or 

 red ; also brick-red. Translucent, some- 

 times transparent. Lustre vitreous, inclin- 

 ing to pearly. Streak greyish-white. Frac- 

 ture uneven : of finely lamellar and fibrous 

 varieties, splinterv. Exhibits double re- 

 fraction. H. 3 to" 3-5. S. G. 2.899. 



Fig. 19. Fig. 20. 



Comp. Anhydrous sulphate of lime, or Ca 



S = lime 41-18, sulphuric acid 58-82 = 100. 

 BB becomes white and is finally covered with 

 a friable enamel. With borax dissolves, 

 with efi'ervescence, to a transparent glass, 

 which becomes yellow or brownish-yellow 

 on cooling. 



Slightly soluble in water and muriatic 

 acid. 



Localities. — English. Granular and of a pale 

 blue colour, in the gypsum-pits at Aston- 

 on-Trent, near Derb}' ; Newark, Notts ; with 

 Gypsum. — Irish. Cave Hill, near Belfast ; in 

 trap. — Foreign. Bex, in Switzerland ; Salz- 

 burg, in the Tyrol ; Wurtemberg ; the Harz ; 

 Hungary; Bavaria; Aussee, in" Upper Aus- 

 tria, of a brick-red colour, in Rock Salt. 



Anhydrite may be distinguished from 

 Gypsum by its greater hardness and specific, 

 c 



