A1LOPHANE. 69 



Oxide of Cerium 33-90. 



Oxide of Iron 25-40. 



Silica 35-40. 



Lome 9-20. 



Alumina 4-10. 



It was discovered at Alluk in East Greenland, by Sir 

 CHARLES GIESECKE, and first observed by Mr ALLAN. 

 It is accompanied by pyramidal Zircon, rhombohedral 

 Quartz, &c. 



ALLOPHANE. 



Allophane. JAM. Syst. Vol. III. p. 531. Man. p. 181. Al- 

 lophane. PHILL. p. 88. 



Reniform, botryoidal, massive : composition impalp- 

 able. Fracture conchoidal. 



Lustre vitreous, inclining to resinous. Colour 

 blue, green, brown. Transparent ... translucent 

 on the edges. 



Hardness = 30 nearly. Sp. Gr. = 1-852 ... 1-889, 

 STROMEYER. 



Without addition it is infusible before the blowpipe. 

 With borax it melts into a transparent, colourless glass. It 

 consists, according to STROMEYER, of 



Alumina 32-202. 



Silica 21-922. 



Lime 0-730. 



Sulphate of Lime 0-517. 



Carbonate of Copper 3-058. 



Hydrate of Iron 2-270. 



Water 41-301. 



It is found at Saalfeld in Thuringia, in the mining dis- 

 trict of Schneeberg in Saxony, and other places. It was 

 first described by Professor STROMEYER. 



