Gg J. Brush on Chalcodite. 199 
a small portion of the iron existed as sesquioxyd. Dr. Mallet 
also communicated his results to Prof. Dana* with the remark 
that he had too little of the mineral for a satisfactory examina- 
tion, and that the results of his analysis could hardly be depend- 
ed upon for even a probable formula. 
_ During the past summer I have had an opportunity of exam- 
ning this mineral at its locality in Sterling, and from the speci- 
mens there collected I have obtained the following physical and 
chemical characters 
inclining to bronze, while the other has more of a yellow color, 
and strongly resembles aurum musivum. Streak olive-green to 
Yellow. The lustre of both varieties is submetallic. Hardness 
ay ° 2, 
=. phorus gives reactions for both iron and silica. cay 
a Twas unable to get enough of the lighter colored variety for 
: What Species they belong, The mineral forming these erys- 
tals is perfectly raat and inkhered the exterior of the crystals 
Tus . . 
Rute and irreoula ly disposed scales. ‘The pulverized mineral is 
decomposed by edie pn acid without gelatinizing; a qualita- 
vi analysis showed the presence of silica, alumina, protoxyd 
5 0 i Ne a 
* This Journal, vol. xxiv, p. 118 
