62 Mineralogical Notices by Prof. Meneghini. 
Oxyd of Zinc.—Occurs on the marmatite. Composition, 
031725 #e47450  H20-825=100 
It is evidently a mechanical mixture, and the oxyd of iron may 
be derived from the Franklinite mixed with the oxyd of zine. 
- Braunite.-—A compact variety from the island of Elba afforded: 
O 3:080, Mn 88-310, #e 4750, Ba 1-025, Si0-751, H2-084—=100, =MnO-+Mn 
Chromic Iron from near Volterra. Analysis :— - 
€r42130 Fe33933  Si4750  2%119-835=100-648 
Silicated Chrome (Wolchonskoite ?) : 
Si2s357 €rs1i2 141333 A 22750100552 
n argillaceous earth containing oxyd of chrome occurring 
near Volterra afforded, 
163158 Pesiss Ers770 Sis025 WH 19-266=-102302 
The point of especial interest connected with these three min- 
erals is, that they have originated from the decomposition of the 
diallage of Euphotide. All the transitions from the diallage to the 
chromic ochre may be traced out. The chromic iron forms seams 
which thin out downward. The metamorphosis seems to have 
been due to ancient sulphur.exhalations, (‘ Soffione,’”’) traces of 
which are still seen in places even now emitting vapor and 
incrusted about with chalcedony. 
I am also indebted to my friend, Prof. Bechi, for several 
analyses of silicates from the Gabbro rosso. 
Caporcianite.—Monoclinic ; the forms are referable perfectly t0 
Heulandite and are very near that species in the angles; M: T= 
131°, a . Cleavage extremely easy parallel to P 
‘and T, and easy also parallel to M: with a light shock the crystals 
fall to acicular fragments. Also in macles, and imperfectly 1a 
diated foliaceous. H.=3-5. G.=2-470. Color flesh-red ; lustre 
arly. Faces M minutely striated. Only the smallest frag- 
ments transparent. Composition: 
i a Meg K Na i 
_ 52015 22938 9675 Tid F112 0250 13268100197 
Formula, 2Ca Sita? 8*+6i. The analysis agrees quite nearly 
with that by Anderson, and we might deduce from it the other 
formula, Ca? Si*+-241Si+6H, which, however, is much less accord- 
ant with analogies. Dissolves easily in acids and forms a jelly 
even in the cold. T'he solution gives a precipitate with oxalate 
of ammonia. Heated in a glass tube, yields water. B.B. fuses 
to a white enamel without intumescence. It occurs in geodes 
incrusted with crystals of calcite in the Gabbro rosso of Mt. de 
Caporciano at L’Impruneta and several other places; and some 
‘times it is accompanied by native copper. ss 
Picranalcime.—Mouometric ; trapezohedral and cubo-trapeZ0 
hedral. Cleavage cubic, very distinct. H. = 5. G. = 2-257. 
