76 J. P. Cooke on Danalite from Rockport, Mass. 
a limited extent at least the breaking up of the last. This is 
what we should naturally ‘expect in an isomorphous mixture, 
the sulphids not being present in separable grains; but diffused 
through the mineral in a state of imperfect chemical combination, 
and thus oe even a firm silicate exceedingly susceptible 
of a 
On owe the results of analysis given above it will 
farther app, in support of the same theory of the constitution 
of the oxyds of zine an n vary very considerably ; these 
metals, although in the seep Cet and determined as 
oxyds, being, in fact, combined t reater or less extent wr 
ened posite as a sesquiox base we shall have for the oxy- 
gen ratio vine — I “ee silica, the pro- 
pene 8:22: : 16°81 or very n Again, the 
sixth of the amount of oxygen in the silicate; so that for every 
twelve equivalents of oxygen in the silicate we have one equiv- 
alent of sulphur in the sulphids. Hence we deduce as the gen- 
eral formula of the min 
(4R,. 48e) Si + 4RS in which R=Fe.Zn. Mn. 
The oxygen ratio of the new mineral is the type ratio of the 
garnet family, and to this family it undoubtedly belongs. Its 
Danatti G . 
Action of to ielieteiaas, saith Gelatinizes, but Decomposed, but 
chloric acid ily and’ does 
Before blowpipe, Fuses on edges Fuses more readily Fuses easily to 
to whi ' to black enamel. a bead, 
Sp. gr. 3°39 to 4, 3°427 3°7 to 42 
Hardness, 55 5°5 to 6. 6°5 to 75. 
Luster, Vitreo-resinous, ditto, ditto, 
eak. 8 
It is true that Willemite and Garnet belong to different erys- 
_ talline systems, but the ordinary form of Willemite really ap- 
