Tenth Supplement to Dana's Mineralogy. 



E [p. 887, I, III, IV].— A new analysis of fihroferrite, fr 

 exposure to tlieair. The mineral is found in botryoidal masses, each rounded nodulaf 



bting built up of innumerable silky fibres diverging from a centre, and having a 

 golden green color. An analysis gave the formula Ve S^+IOH. On exposure to 

 the air for two weeks it lost two equivalents of water ; a longer exposure of many 

 months proiiuced no further change ia composition. Heated at 212° F. it was con- 



verted into 5'e S2+3fi. 



Coffer [p. 17. IV, VI-IX].— The pseudomorphotis crystals of copper aft 

 uragonit.^, described by Kenngott (Soppl. V), have been examined by D. Forbe 

 (QiMT. Jmir. Geol. Soc, London, xvii, 45). Crystals are found in the copper min. 

 others have a nucleus of Srbonatrof Ume, from^hif h Forbes infers that the pse 





i- Alger has described what he considers to be a rhombohedron of copper. Iron 

 Copper Falls Mine, (Lake Superior). It is associated with rbombohedml carbon- 

 ate of lime, and the copper is thought by Alger to be pseudomorphous of calcite. 

 Dr. Jackson suggests that the crystal may be a cube, which slightly distorted, gives 

 "a rhombohedral aspect {Proc. BosL Soe. Nat. Hut, viii, 171). 



Copper Glaxck [p. 46, 505].— Dr. Genth has made a rery elaborate series 



§|£^JJudomor^^^^^ 



2f"-'^d galei^^lll roon"after Mr^Trippel, of the' Tennessee ^"PP/;''j*^j'"^^''',gj.g 



and lia™epidote!^'^The''I>nSUTs°pSL between 'dark lead gray 



adduced from the analyses of seven specimens gave the following : 



Copper-glance, 70-26 78-82 81-05 8989 93-80 8C 



Analysis 2 by Trippel, the others by Genth. The author q""'^^ jj^/jf .^.J' 

 ^Cu^S+Pbs, and cuproplumbite Cu^S^-iPhS may not also P^"^f f ^^ £ 

 S'lS^ "^"PP^^-glance after galena in an unfinished condaiou-(tbi. Journal 



CoPFEa-XtcK^i. [p. 52, VI-VIII].-Analysis of copper-nickel 

 "7 a. Hahn (fi. and 11. Zeitung, xx, 281) : 



Sn, i?81 50-94 5^69 O^ls 's'o = 10082 



(^'n/ptomorphite.—Bee Boeonatrocalcite. 



-1-2. G.=3.~{KennqoH, Uebenicht, I860, 57.) 

 ^- JocE. Sci.-Second Series, Vol. XXXIV, No. IOI.-Seft., 1SC2, 



