analysis, who obtained 28 parts o f oxide of zinc, and nearly 17 parts
of sulphur from too parts of the mineral. Ekeberg is a very exact experimenter,
but not so well qualified to distinguish the appearance of
minerals, as his eyes are bad. Hence he might have easily overlooked
a mechanical mixture of blende in the crystals. That this should have
been overlooked likewise by Vauquelin. and Haiiy, is not so easily accounted
for; unless we suppose that they were not possessed o f any
great stock o f crystals to examine. And we may very well suppose
the mixture to be so intimate in some cases as to escape the eye altogether.
The crystallization of automalite and spinell are exactly the
same. The result of Ekeberg’s. analysis is as follows :
Alumina 6 o-oo
Oxide o f z in c ............... 24*25
Oxide of iron . . . . . . . . . . 9'25
Silica ........................ 4*75
Manganese and lime Trace
Loss ........... .. 1 "75
lO O ’OO
There is one objection to considering automalite as a spinell mixed
with blende, and I conceive it to be a very formidable one: the specific
gravity of automalite is not only considerably greater than that of
spinell, but even greater than that of blende itself. One cannot therefore
see how it can consist of a mere mixture of the two. And if they
be chemically combined, automalite ought to constitute a new species.
The colour of the automalite, which is green, does not occur in any
variety of spinell that I have ever seen. The magnesia, which seems
to constitute an essential constituent of spinell, is wanting in the
automalite. These circumstances ought to make us hesitate, and not
venture to class the two minerals together till the subject has been
farther examined.
Besides in the mine of Eahlun, automalite has been found likewise
in the mine of the Nefverberg, and in the mine of Easter Silberg, the
first very near Fahlun, the second at the distance o f about 27 miles.
4 . There is another mineral which occurs likewise in Eric Matt s
mine, to Which the name o f fahlunite has been given. I do not recollect
to have seen any description o f it given in any mineralogical book,
1 regret, therefore, that my description from simple recollection must
be too imperfect to convey a very accurate picture o f the stone. Its
colour varies considerably. I have seen it red, green, brown, whitish
yellow, and grey. It is sometimes compact, and sometimes crystallized
in six-sided prisms : it affects likewise other forms, but I do not recollect
them sufficiently for description. Its principal fracture is foliated,
its cross fracture splintery. It is translucent on the edges. Its specific
gravity is 2 -6 6 . It is semihard, and easily scratched by the knife. Before
the blow-pipe it melts into a whitish bead, after running through
several changes o f colour. Ho analysis of this mineral has hitherto
been made; nor has it been ascertained by any competent judge,
whether it really ought to constitute a distinct species, or to be joined
to some of the species o f stony minerals already known.
5. A t Finbo, about three miles from Fahlun, there is a quarry. The
rock consists chiefly o f quartz, though it belongs in fact to the gneiss
rocks o f the country. About the year 1805, Assessor Gahn discovered
in tips rock a mineral, which was soon after described by Hisinger, and
analysed by Berzelius. The description and analysis was published in
the first volume o f the Afhandlingar i Fysik, Kemi och Mineralogi,
published in 1806. They gave it the name of pyrophysalite, from the
great number o f vesicles which appear in it, when treated before the
blow-pipe.
The colour of this mineral is white, sometimes inclining to light
green. It is usually crystallized in a kind of irregular rhomboidal
prism with angles of 62° and 1 18°. It is so very full of rifts that complete
crystals of it o f any considerable size can seldom be obtained. 1
saw one, however, in the mineralogical cabinet o f Upsala. Small
sized crystals are not uncommon. It is common likewise to find the
crystals of this mineral enveloped in the rock from which they were
extracted.
It readily scratches glass, and strikes fire with steel; but is itself
2 g 2