J. P. Cooke on Danalite from Rockport, Mass. 73 
Art. XI.—On Danae a new Mineral Species from the Granite 
of Rockport, Mass.; by Jos1an P. CooKgE, Jr. 
na saps through the —s granite, which is quar- 
ried at the extremity of Cape Ann, Massachusetts, and much 
used for building in ner. ea shadie vicinity, are Deckaioad 
grains of a flesh- red mineral somewhat resembling Rhodonite. 
The mineral has been at times found in masses of considerable 
size, and for a specimen of this sort I am indebted to the kind- 
ness of Mr. W. J. Knowlton, of the re Scientific School. 
The characters of the mineral are as follows: Color, flesh- 
red to gray. Streak similar in color to the scare but lighter. 
Lustre, vitreo-resinous. Translucent. Fracture subeonchoidal 
uneven. Brittle. Hardness 5: 5 to 6.. Specific gravity—two de- 
terminations—3°427. e exterior portion of the mass showed 
no indication of bayatallind form and there was no distinct 
Il 
to the longer md of the face. The m eral, therefore, crys- 
tallizes in the holohedral forms of the cneiasieie system. 
Before the blowpipe the mineral readily fuses on . the edges to 
a black enamel. Hence its fusibility is about 4 of von Kobell’s 
scale. On charcoal with carbonate of soda it gives a slight 
coating of oxyd of zinc. In a closed tube it loses color, but 
gives off no water or any sublimate. It is perfectly decomposed 
after some time b hydrochloric acid, the silica partly gelatiniz- 
ing. It is also decomposed by nitric acid; but then the silica 
separates as a powder. It is partially decomposed by dilute sul- 
phuric acid, and even by acetic acid, sulphid of hydrogen gas 
being evolv 
In order to thoroughly decompose the mineral the material 
was finely pulverized and sealed up with some concentrated 
acid in a glass flask, which was then exposed for several hours 
to the heat of a water-bath. When hydroehloric acid was used 
a slightly greenish solution = —- frequently depositing 
crystals of protochlorid of i oling, but showing no 
traces uichlorid, and Fm ane the flask a strong ‘odor 
of sulphid o hydrogen was observed. When nitric acid was 
used the flask became filled with nitrous vapors, and both the 
iron and the sulphur were completely oxydized. A qualitative 
analysis eg roved tha mineral to be a compound of silica, glucina, 
protoxyd of iron, oxyd of manganese, and oxyd of zine, mixed 
with the sulphids of the last three met: presence 
Am. Jour. Sc1.—Srconp Serius, Vou. XLII, No. els, 1866. 
