TWO NEW MINERALS. 



MEDJIDITE (SULPHATE OE UKANIUM AND LIME)— LIEB- 

 IGITE (CARBONATE OE URANIUM AND LIME). 



The minerals here alluded to were found associated with a 

 specimen of pitchblende from the neighborhood of Adrianople. 

 Turkey ; it was quite impure, and a portion of it contained 

 crystals of copper pyrites. On the surface of the pitchblende, 

 besides the two minerals in question, there existed crystals of 

 sulphate of lime and a little oxide of iron. 



Medjidite (Sulphate of Uranium and Lime). 



This mineral is of a dark-amber color, transparent, of im- 

 perfect crystalline structure, fracture vitreous, although the 

 surfaces exposed are sometimes of a dull-yellow color, arising 

 from the loss of water. It is found on the surface of the pitch- 

 blende associated in some places with crystals of sulphate of 

 lime. Hardness about 2.5 ; specific gravity not known. 



Chemical Characters. — Heated gently it loses its water, be- 

 coming of a lemon-yellow color. Heated to redness it blackens 

 (being converted into oxide of uranium and sulphate of lime). 

 It is insoluble in water, but dissolves readily in the smallest 

 quantity of dilute hydrochloric acid ; (in this way, had it been 

 necessary, I might have separated it from any adhering sul- 

 phate of lime.) The acid solution gives a tolerably abundant 

 precipitate with hydrochlorate of baryta, and a red-brown 

 precipitate with ferrocyanuret of potassium ; bicarbonate of 

 ammonia forms a precipitate that is redissolved by an excess 

 of the ammoniacal salt ; oxalate of ammonia added to this 

 solution demonstrates the presence of lime. Farther exami- 

 nation detected no other substance. 



So far as the small quantity at my disposal enabled me to 

 make out its composition, it would appear to be a salt similar 



