186 HYDROSTEATITE. 



Water and carbonic acid . 5*06 



Insoluble 



2-19 



100-0 



Name. From ^Sa;^, water, and silex. 



The name Hydrosilicite has also been 

 given to Kerolite. 



Hydrosteatitb. a Steatite from Gop- 

 fersgriin, containing, according to Klaproth, 

 only 59-5 per cent, of silica. This variety 

 is remarkable for containing psendomor- 

 phous crystals, probably after Quartz. 



Hydrotalc, Necker. See Pennine. 



Hy]>rotalcite, Hochstetter. A variety 

 of Volknerite, in which part of the alumina 

 is replaced by peroxide of iron. It is foli- 

 ated pearly, with a greasy feel. Translu- 

 cent, or transparent in thin folia. H. 2. 



Comp. Mg6 (A:li^e) + 16H. 



Analysis, hy Hochstetter : 



Alumina .... 12-00 

 Peroxide of iron . . . 6-90 

 Magnesia .... 3trn0 

 Carbonic acid . . . 10-54 

 Water ..... 32-06 

 Insoluble . . . .1-20 



99-60 

 Locality. Snarum, in Norway. 

 Name. From i^i/c^z, water, and talcite. 

 Brit. Mus., Case 19. 



Hydrous Aluminate of Lead, Smith- 

 son. See Plumbo-Eesinite. 



Hydrous Anthophyllite, Thomson. 

 This mineral has been re-examined by 

 Smith & Brush, who found it to contain 

 only 2*26 per cent, of water, instead of 11-45 

 per cent, as stated by Thomson. According 

 to Dana, it is altered asbestiform Actinolite. 

 Analysis, mean of two, by Smith §" Brush : 



Silica 58'43 



Magnesia .... 29-34 

 Protoxide of iron . . .8-^6 

 Soda ..... 0-88 



Potash trace 



Alumina .... trace 

 Water 2-26 



99 67 



Localities. Girvan, in Argyleshire, in 

 fibro-columnar masses, of a greyish-brown 

 colour. New York Island. 



Hydrous Apatite. SeeHYDRO-APATiTE. 



Hydrous Borate of Lime and Mag- 

 nesia. See Hy^drobouacite. 



Hydrous Carbonate of Lime, Scheerer. 

 See Hydrocalcite. 



Hydrous Diphosphate of Alumina 

 AND Magnesia, Thomson. See Lazulite. 



Hydrous Iolite, Bonsdorff. A variety 



HYPERSTHENE. 



of altered Iolite, occurring in regular six- 

 sided and tAvelve- sided prisms, with a basal 

 cleavage, which is sometimes perfect. Co- 

 lour greenish-brown, with a pearly lustre. 

 Translucent. Folia brittle. Kather harder 

 than Calc-spar. 



Comp, Iolite + 6H. 



Analysis, bv Bonsdorff: 



Silica .' . . . . 45-03 

 Alumina . . . .30-05 



Magnesia .... 9-00 



Protoxide of iron. . . 6-30 



Water 10-60 



100-00 

 BB becomes paler but does not fuse. It 

 is not completely decomposed by acids. 

 Locality. Abo. 

 Hydrous Muscovite. See Margaro- 



DITE. 



Hydrous Oxide of Iron, Phillips. See 

 Limonite. 



Hydrous Phosphate of Copper, Allan. 

 See Phosphocalcite. 



Hydrous Pyrites. A variety of white 

 Iron Pyrites (Marcasite) containing water 

 m a state of chemical combination. H. 3 to 

 4. S.G. 4-925 to 5. 



Locality. Moravia, Upper Silesia. 



Hydrous Steatite. See Saponite. 



Hydrozincite. See Zinc Bloom. 



Hypargyronblende, Breithaupt, or 

 Hypargyrite. a variety of Miargyrite, 

 from Clausthal, in the Harz, According to 

 Plattner, it contains 35 per cent, of silver. 



Hypersthene, Haiiy, Phillips. Occurs 

 massive or imbedded in rocRs. Colour 

 greyish or greenish- black, with a lamellar 

 structure, and a bright metallic pearly lus- 

 tre. Translucent in thin laminiB, with a 

 slight tinge of green, when viewed in one 

 direction, but opaque in the other. Streak 

 dark grey. Cleaves parallel Avith the diago- 

 nals and' sides of a rhombic prism. Very 

 tough. Fracture uneven. Surface of frac- 

 ture resinous. H. 6-0. S.G. 3-3 to 3-6. 



Comp. R 'Si2, in Avhich K represents lime, 

 magnesia, and a large proportion of prot- 

 oxide of iron. 



Analysis, from Florence, bv Kohler : 

 Sibca . . . ."' . 53-20 

 . Alumina .... 2-47 

 Magnesia .... 14-91 



Lime 19-09 



Protoxide of iron . . . 8-67 

 Protoxide of manganese . 0-38 

 Water . . . . .1-77 



100-49 



