excepted, is built o f wood. I think it but fair to say that the inn at
Nykoping was the best 1 met with in Sweden.
Next morning about seven (for it is difficult to get away early from
a town in Sweden) I set out on my proposed visit to Tunaberg; a copper
mine of some celebrity in consequence o f the considerable quantity
o f cobalt ore which it yields. Tunaberg lies within about two English
miles of the sea, near the commencement of the bay of Bronick, which
runs a good way inland, and terminates not far from Norkoping. It is
1A Swedish miles, or 1 1 1. English miles from Nykoping The road to
it is a bye-road, narrow and intricate, winding through a very hilly,
wild, and romantic country. The morning was unfortunately hazy,
and it began at last to rain, so that my view was in a great measure i n-
terrupted: but it cleared up about mid-day, and the afternoon and
evening were very clear and fine. The hills, which as usual were very
low, were all covered with pines.
The rocks at Tunaberg are very distinctly gneiss, and the ore lies in
veins, which as far as I could make out run in an easterly direction.
There are two different mines wrought at Tunaberg, a copper mine
and an iron mine, but neither of them to any great extent. The copper
mine is the most westerly o f the two, and is likewise the most important.
The vein is filled with limestone, in which copper pyrites is
scattered in no great abundance. Cobalt glance, usually in crystals, is'
scattered through the limestone likewise, and in no great quantity.
Sometimes also galena is observed. Formerly it existed in such quantity
that lead was obtained from i t ; but o f late years the proportion of
galena has diminished so much that this branch of mining has been
entirely laid aside. Formerly pieces o f serpentine were likewise found
occasionally in the same vein; but for some time back they have
disappeared.
The glance cobalt crystals are usually cubes, or octahedrons, or dodecahedrons,
or icosahedrons; all of which occur of a very considerable
size. The cobalt ore is picked out with considerable care, reduced to
a coarse powder, and made up into bags, which are all exported to
England, where the ore is in great request for the use o f the potteries.
I saw a number o f bags o f it made up for sale, and labelled in English,
sulphureted oxide o f cobalt from Tunaberg. The only analysis of this
ore, of which we are possessed, is that o f Tassaert, who found its constituents
as follows:
Arsen ic ...................................... 49-00
Cobalt. ............................ . 36-66
I r o n .......................................... 5-66
S u lp h u r ................................... 6-50
L o s s .......................................... 2-18
1 0 0 -0 0
I f this analysis be correct, the title sulphureted oxide o f cobalt by no
means applies to this ore. It seems rather to be an alloy of arsenic and
cobalt.
There occurs in this mine occasionally a very beautifiil variety of
green-coloured felspar, which was first particularly observed by Mr.
Svedenstierna. Its colour varies from light to dark green. It consists
of a congeries o f small distinct crystals, which seem to be six-sided
prisms, with pointed extremities. External lustre small; internal,
splendent: translucent. Specific gravity 3 -i 84g. Before the blowpipe
it melts into a transparent, slightly-greenish bead; and i f the
heat be continued, it swells and froths.
The limestone which occurs in this vein contains manganese as
one of its constituents. When burnt, it loses 0'40 of its weight.
Cronstedt, in his Mineralogy, describes various kinds of copper ore,
as malachite, copper pyrites, and grey copper ore. But the only
copper ore that I was able to discover was copper pyrites, and even
that in no great quantity, comparatively speaking.
In what is called the Mormorgnfvan, at Tunaberg, there occurs a
mineral which deserves to be mentioned. I did not myself see any
specimens of i t ; but there is a description and analysis o f it, by
Mr. Hedenberg, published in the second volume o f the Afhandlingar,
i Fysic, Kemi, och Mineralogi, p. 164. From the description, one