62 Mr Alger on New Localises of Bare Minerals. 



YttrO'cerite. — This rare mineral is found, associated with Brucite, 

 in rolled masses of limestone, in the town of Amity, Orange county, 

 New York. I have, as yet, seen but two specimens of it, which I 

 found among some fragments of limestone containing Brucite and 

 mica, in the duplicate collections belonging to the late Dr Horton, of 

 Edenville. It attracted my attention as being unlike fluor-spar, 

 which it was supposed to be at the time, and I have now satisfied 

 myself that it is Yttro-cerite, though I have not gone so far as to 

 detect the Yttria, the presence of which in the mineral cannot be in- 

 dicated by mere blowpipe experiments alone. It has no crystalline 

 structure, but appears in thin layers, or seams, which sometimes 

 amount to scarcely anything more than peach-blossom, or purple 

 stains, penetrating the seams of the limestone ; precisely the charac- 

 ter of this mineral in the specimens I have of it, from Finbo in 

 Sweden. With this it also agrees in hardness and colour. When 

 heated in a glass tube, it slightly decrepitates, shews no phospho- 

 rescence, gives out moisture, and becomes milk-white ; at the same time 

 there is a perceptible burnt smell. When its powder, moistened with 

 sulphuric acid, is placed in a platinum crucible, hydro-fluoric acid is 

 given out by the application of heat, and the usual reaction on glass 

 is produced. The pulverized mineral, heated with fused salt of phos- 

 phorus in an open glass tube, also shews the same reaction, the glass 

 losing its polish where the moisture is deposited. In these experi- 

 ments I was careful to separate the mineral entirely from the Brucite ; 

 but I have not been able to obtain fragments sufficiently free from 

 carbonate of lime, to enable me to give its blowpipe characters in de- 

 tail, or subject it to any other trials. I hope to be able to obtain 

 better specimens at an early day, and then to complete its examina- 

 tion. The mineral is very characteristic, and^ in the hand specimen, 

 cannot be distinguished from the Finbo variety. 



Ottr elite identical with Phyllite. — ^The name of Phyllite, from 

 (puWoVy a leaf, was given by Dr Thomson to a mineral, which was dis- 

 covered and sent to him for analysis by Professor Nutall. It comes 

 from Sterling, Massachusetts, and is disseminated in small thin plates, 

 through what appears to be an argillo-micaceous slate. Some of these 

 plates are angular and others rounded, not appearing to have any re- 

 gular crystalline form ; yet, in a few instances, they present the dis- 

 tinct form of rhomboidal tables. Colour, brownish-black, or greyish- 

 black ; lustre, shining and semi-metallic ; opaque ; fracture, uneven. 

 The knife makes a faint impression upon them. In strong transmitted 

 light, the thinnest discs present a greenish colour. Before the blow- 

 pipe, on charcoal, it becomes magnetic, but does not fuse even on the 

 edges ; with double its bulk of borax, it slowly dissolves into a dark 

 iron green glass. Its composition, as stated by Dr Thomson, is as 

 follows : 



