276 Prof. Fuchs on Lasionite and Wavellite. [Oct. 



Article VIII. 



On Lasionite and Wavellite. By Dr. Joh. Nep. Fuchs, Profes- 

 sor of Chemistry and Mineralogy at Landshut. 



In the 18th volume of Schweigger's Journal, p. 288, I inserted 

 a short notice of a mineral, to which, from its hair-form crystal- 

 lization, I have given the name of lasionite. It is found in the 

 ironstone mine of St. Jacob, in the Upper Palatinate, where it 

 occurs very sparingly scattered in the brown ironstone. ,This 

 mineral has been lono- known and considered as a feather zeolite, 

 to which, in its external characters, it has a very strong resem- 

 blance. I found its constituents to be alumina, phosphoric acid, 

 and water. This authorized me to make a peculiar genus of it, 

 as no mineral composed of the same constituents had been 

 hitherto known. It occurred to me, however, that wavellite, 

 which I had not yet seen, might be nearly of the same nature 

 with it ; but I could not listen to this suspicion, as three of our 

 most celebrated chemists, Klaproth, Davy, and Gregor, who had 

 analyzed this mineral, had found nothing in it but alumina and 

 water. Since that time, however, I have satisfied myself by 

 experiment that wavellite not only contains phosphoric acid, but 

 that in its chemical composition, it agrees exactly with lasionite. 

 What follows will show this. 



Examination of Lasionite. 



Lasionite is infusible before the blow-pipe ; but it gives the 

 flame a bluish-green colour, and thus betrays the presence of 

 phosphoric acid. With carbonate of soda, it froths, and melts 

 into a doughy mass. When heated to redness, it loses, accord- 

 ing to a careful and very accurate experiment, 28 per cent, of its 

 weight. It dissolves completely in muriatic and nitric acid, as 

 well as in caustic potash or soda ; but the solution takes place 

 much more easily and rapidly in the alkalies than in the acids, 

 which must be employed in considerably greater quantities. 

 When acetate of lead is dropped into the nitric acid solution, 

 only a very small precipitate of phosphate of lead falls, when the 

 excess of acid has been previously saturated with ammonia 

 Sal-ammoniac throws it down* unaltered from the alkaline solu- 

 tions, and when ammonia is digested on the precipitate, it takes 

 up but a very small proportion of the phosphoric acid. This 

 shows us the difficulty of completely separating the phosphoric 

 acid from the alumina. I was not completely successful in 

 accomplishing this separation in my former experiments. By 

 repeating my experiments, which I have been enabled to do by 

 the goodness of Prof. Graf, who sent me some new specimens 

 of the mineral from a fresh opening, I have obtained results 

 which differ considerably from my former ones. I performed the 



