* 
Miscellanies. 387 
6. Violan, a silicate of alumina, magnesia, lime, much protoxide of 
iron and soda, and occurring at Piedmont with manganesian epidote ; has 
waxy lustre, deep violet blue color, nearly conchoidal fracture, amor- 
phous, opaque, uneven, brittle, sp. gr. 3.233, does not change on 
ing, but may be brought by a higher temperature to a clear bead. — 
7. Tombacite, an arsenical nickel ore, with a little sulphur, and 
mall trace of iron or cobalt, occurring near Lobenstein in Voigtland ; 
in color it resembles the magnetical iron, sometimes with a greenish 
brown hue ; its streak is black, appears to belong to the hexahedral 
system, is brittle, non-magnetic, sp. gr. 6.637. 
8. Hepatic blende, a mineral mostly wax-yellow, from Saxony, in 
the mine Hochmuth near Geier, Himmelreich-Erbstollen, between 
Marienberg and Wolkenstein, and also from Cornwall. The color varies 
from pea yellow to pink brown, transparent; the streak is either col- 
orless or yellowish gray, forms botryolitic and reniform conglomerates, 
fracture conchoidal, and a sp. gr. 3.7 to 3.78, and, according to Platt- 
ner’s experiments, is said to be a sulphocarbonate of zinc, it containing 
zinc, sulphur, and carbon. It decrepitates on heating, yielding water 
and a little sulphur, smells like sulphuretted hydrogen, and then like 
coal tar, and then becomes gray ; it is decomposed by hydrochloric 
acid, disengaging sulphuretted hydrogen ; the gray substance remaining 
from before is soluble in nitric acid, leaving sulphur and carbon, the 
first of which may be val and separated. 
It may be inferred from the experiments of Plattner, that this mineral 
consists of sulphuret of zinc formed by water, and intensely mixed with 
bitumen or other carbonaceous compound ; for it is not to be presumed 
to contain any carburet of sulphur, which would in those instances distil 
over unchanged, unlike the above. 
Hess has described a new mineral, which he calls Volborthite, consist- 
ing of vanadiate of copper, of yet undetermined degree of combina- 
tion. It forms crystalline needles of olive green color, papillary ; is 
translucent in splinters, has a yellowish green streak, and a sp. gr. 3.55; 
on heating grows black, yields a little water; it melts before the blow: 
pipe, and by increased heat yields a slag like graphite, extending upon 
the charcoal with some metallic copper; by soda the copper is redu- 
ced instantly, and vanadious soda is formed. 
Gigantolite,* by Nordenskiéld, from Tammela, Finland. One of the 
crystals of that mineral measured two and a half inches in diameter. 
This mineral resembles the Fahlunite, and all the harder varieties of 
rs patae eS 
* What name could we give to our gigantic We of beryl, topaz, apatite, 
tourmalines, zircon, rhomb-spar, lead, fluor-spar ; the fo raWae peel 
New York, some of which measure twelve to fifteen sick in 
