378 Prof. B. Silliman, Jr n on some American Minerals. 



V. Analysis of a granular Albite, associated with the corundum 

 of Pennsylvania, and a new analysis of the Indianite of Bournon. 

 VL On Boltonite, and Thomson's Bisificate of Magnesia. 

 VII. On Nuttallite of Brooke. 



I. Species of the Family Mica. 



This series of minerals, forming a new and very interesting 

 addition to the mica family, is found associated with the corun- 

 dum of Pennsylvania, and one or more of the species are proba- 

 bly associated with corundum in every locality where the latter 

 is found. My attention was first called to these minerals by re- 

 ceiving from Dr. J. L. Smith, now in Constantinople, a small por- 

 tion of a similar mineral which he has called Emerijlite.* . The 

 quantity of this mineral received (only 0-2 gramme), was quite 

 too small to enable me to obtain more than its general characters. 

 As this mica was the means of calling my attention to the others, 

 I will repeat the results of Dr. Smith, with such additional char- 

 acters as were obtained here. 



Emerylite. 



This mineral is found associated with the emery from the J 



localities of Asia Minor. It is in brilliant micaceous scales, 

 brittle and inelastic. Color — gray with a tinge of lilac ; lamina? 

 easily separable. Hardness 3-3*25. Gravity not satisfactorily 

 determined on so small a quantity. B. B. alone in forceps ex- 

 foliates, whitens and emits a very brilliant light, but does not 

 fuse. In close tube yields water which gave a feeble reaction 

 for fluorine. Dissolves in borax to a clear glass, and leaves a 

 siliceous skeleton in salt of phosphorus. The reactions for 



* * • • W m 



Si AI Ca Fe and K, are satisfactory. It is not acted on by strong 

 acids ; even by long continued boiling with Nordhausen sulphuric 

 acid very imperfect decomposition was effected. 



Fused with carbonate of baryta, a qualitative analysis gave re- 

 actions for silica, alumina, peroxyd of iron, lime and potash, with 

 a trace of soda. 



I was unable however, with the most exact care, to confirm 

 Dr. Smith's observation of the existence of zirconia — probably 

 a larger portion of the mineral might give a different result. 



Dr. Smith gives the following as an approximate result of the con- 

 stitution of the " Emerijlite" from several analyses made by himself 



Silica, ...... 30* 



Alumina, 50- 



Zirconia, ..... 4* 



Lime, ...... 13' 



Oxyd of iron, mang., and potash, . 3- 



loo- 



* See this Jour., vol. vii, 285. 



