Scientific Intelligence. — Mineralogy. 385 



account of the Island of Ascension, published in a former num- 

 ber of this Journal, a modern calcareous formation is mentioned, 

 and rocks of the same description occur in Scotland, 



MINERALOGY. 



17. Hydrosilicite, a new Mineral Species. — Dr Kuh, in his in- 

 augural discourse, entitled " De Hydrosilicite, nova fossilium 

 specie, Berlin 1 826,"''' informs us, that he found, in the serpentine of 

 Frankenberg in Silesia, along with chrysoprase,opal, and pimelite, 

 a mineral which he names Hydrosilicite. It is white, without 

 lustre, feels greasy, translucent, fracture even, soft, does not ad- 

 here to the tongue, amorphous, and appears to be almost entire- 

 ly composed of pure silica and water. 



18. Chrornein differ e7it Minerals. — According to Walchner's 

 experiments, chrome occurs not only in the different varieties of 

 olivine, but also in several other minerals, in which magnesia is 

 a constituent part, as in many steatites, actynolite, all serpentines, 

 greenstone, basalt, &c. 



19. Fluoric and Muriatic Acids in Apatite. — Gustave Rose 

 finds that apatite contains not only muratic acid, but also occa- 

 sionally a considerable portion of fluoric acid. 



20. Glaulwlite, a neiv Mineral Species. — -This mineral, found 

 by Menge in Siberia, occurs imbedded in a compound of com* 

 pact felspar and granular limestone, which sometimes contain 

 scales of talc. Its colour is lavander blue, which sometimes 

 passes into green. It is translucent on the edges, with a splintery 

 fracture, vitreous lustre, a hardness intermediate between that of 

 fluorspar and felspar, and a specific gravity of 2,721. Accord- 

 ing to Dr Bergemann it contains the following constituent parts : 

 Silica 50.583; Alumina 27.600; Lime 10.266; Magnesia 3.733; 

 Potash 1.266; Natron 2.966; Oxide of Iron 0.100; Manganese 

 0.866; Loss 1.733. = 99-113. The iron and manganese are not 

 essential constituent parts of glaucolite, as is shewn by the range 

 of colour extending from blue to white. The magnesia appears to 

 be derived from the talc scales. Hence if silica, alumina, and lime 

 with alkali, be considered as the constituent parts of glauco- 

 lite, the following will be their proportions ; Silica 54.58; 

 Alumina 29.77; Alkali 4.57; Lime 11.08= lOO.OO.—Pcgg-m- 

 drofs Annalen, St. 2. 1827. 



JULY — SEPTEMBER 1827. B h 



