138 Notice of Danburite, a new Mineral Species. 
Mineralogical Description. 
Primary form: _ Oblique rhombic prism. 
Cleavage parallel with P indicated obscurely by fissures. - 
Lustre vitreous, in a high degree. Color shades of honey yel- 
low. Streak white; transparent. (The decomposing variety is 
nearly white, translucent and very fissile.) 
Hardness = 7.5. Sp. Gr.=2.83. 
~ Chemical Description. 
When heated alone before the blow-pipe, it phosphoresces and 
fuses slowly without intuméscence into a white blebby, transpa- 
rent glass. . With borax, it melts with effervescence into a trans 
parent globule. When heated in a glass tube, it emits moisture. 
In the condition of an- impalpable powder, it is taken up by by- 
‘dro-chloric acid after long digestion. 
By the requisite trials, it was found to contain neither fuciic, 
boric, nor phosphoric acid. By heating, it lost 8 p. c. in weight. 
By ignition with twice its weight of anhydrous carbonate of 
soda, it fused into a white mass, which formed a colorless solu- 
tion with dilute hydro-chloric acid. After the separation of the 
silica, which weighed 56 p.c., the solution was precipitated by 
‘ammonia, and the precipitate treated with carbonate of ammonia 
solution in large eXCess, which after-frequent agitation and some 
time standing was partially evaporated ; a pale: yellow pellicle in- ° 
vested the sides of the capsule, which after drying weighed 0.85 
p-c. It was treated with hydro-chloric acid, and the solution 
obtained afforded when tasted no impression of sweetness. Its 
yellowish color and easy solubility after ignition in hydro-chlori¢ 
acid proved it not to be zirconia ; while the absence of sweetness 
showed that it was not glucina, It seems most probable: there- 
fore, that it is yttria. 
~The portion of the precipitate by ammonia. not taken up. by 
the carbonate of ammonia, was treated with a solution of potassa. 
It was instantly dissolved, and on being precipitated with hydro- 
chlorate of ammonia, washed and ignited, it amounted to 1.7 p. ¢ 
_ The clear hydro-chloric solution from which the alumina and 
yttria? had been separated was precipitated by oxalate of ammo- 
nia, ome noe pein 5 was washed and ignited. bigaed residuum 
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