Scientific Intelligence — Mineralogy. 379 



the first is most esteemed. — (^American Journal of Science and 

 Arts, vol. vii., Second Series, No. 20, March 1849, p. 285.) 



12. Randanite, a native Hydrated Silica from Algiers. By 

 M. Salvetat. — This hydrated silica exists abundantly near Algiers, 

 and was taken for Kaolin. It is pulverulent and friable, forming 

 an excessively light powder. It is infusible, but loses colour and be- 

 comes grayish, contracting a little. It gives out water at 16° C, 

 but still retains a portion at 100° C, losing the whole only at an in- 

 tense heat. It was found to consist of 80 parts of gelatinous silica, 

 9 of water, 6-48 of insoluble silica, with 1-41 alumina, 0-55 oxide 

 of iron, 0-56 lime, 2' 00 of potash, soda, and loss, and a trace of 

 magnesia. Of the water 4-04 per cent, escaped at 16° C, and 

 3-96 at 100° C, and 1 per cent, is combined with the alumina. 



The composition resembles that of a similar material from Ceys- 

 sat, and near Randan, in the Puy de Dome, analysed by M. Fournet. 

 This chemist obtained in his analysis, gelatinous silica 87'20, water, 

 carbonic acid, and organic matters 10-00, alumina and oxide of 

 iron 2-00, sand by decantation 0-80, with traces of lime, mag- 

 nesia, &c. — (^Ann. de Ch. et de Phys., November 1848, t. xxiv., 

 p. 348). 



13. Analysis of Lardite from near Voigtsherg, in Saxony. — 

 Lardite, which has been referred to agalmatohte, is an anhydrous mag- 

 nesian silicate, consisting, according to Karsten's analysis, of silica 

 66-02, magnesia 31-94, protoxide of iron 0-81, soda and potassa 0-75, 

 loss by ignition 0-20, chloride of sodium and sulphate of potash, a 

 «race = 9 9-72. It whitens before the blow-pipe, and in a tube 

 gives no trace of moisture, but exhales a disagreeable odour, like many 

 other magnesian minerals. In the exterior flame it becomes wax 

 yellow. It dissolves slowly but completely in borax, forming a 

 glass which is pale yellow when hot, but becomes white on cooling. 

 Density 2-795. — Karsten (Jour, fur Prak. Cliem., xxxvii., s. 162.) 



14. Neolite, a new Mineral. — Neolite is a talc-like mineral from 

 some old mines near Arendal, Norway, where it occurs as modern m- 

 crustations in fissures, and on detached stones. It is often crystalline, 

 eithei- in folia or in concentric fibrous aggregations like Waveilite. 

 It is greenish, with a greasy lustre, and a specific gravity 2-77 after 

 long desiccation. Hardness, that of talc. The analyses vary much. 

 In one, Scheerer obtained silica 52-28, alumina 7-33, magnesia 

 31-24, protoxide of iron 3-79, protoxide of manganese 089, lime 

 28, water 4-04 = 99-85. In another, silica 47-35, alumina 10-27, 

 magnesia 24-73, protoxide of iron 7-92, protoxide of manganese 

 2-64, water 6-28 = 99-19. — M. Scheerer. 



15. On Volknerite, a new Mineral from the Mines of Schischimsk. 

 By M. Hermann (Jour. f. Prak. Ch., xl. 11). — Volknerite occurs 

 in white pearly laminae on talc-slate, and sometimes in hexagonal 

 tables, witli a perfect basal cleavage. Feel greasy ; density 2-04 ; 

 composition Al 3 II + 6 (Mg 2 li). 



