Fröå copper mine, Jämtland

DESCRIPTION

When talking about the Fröå mine, it is often meant the Gustavs and Fröå mining fields.
Fröå mine is situated at the south east side of Åreskutan, a big fjell in Jämtland. It is surrounded by alpine birc trees.
The first mining of Fröå and Bjelkes mine was around 1750 and it continued in periods until 1919 when the last mine was closed. During this period the two mines produced about 3000 tons of copper.
The rock dumps were worked over once more by an American company. It was believed that the old time mining had missed a lot of the ore, but it showed that it was too expensive to get the last copper out of the rocks. The company went bankrupt and since then the mine have rested.
in the late 1980:s a restauration project was started. During the following years a number of mining buildings were rebuilt. Today it is a historical protected site, and no mineral collection is allowed at the main site.
There are a few smaller mines in the area surrounding the main mine where minerals still could be collected.

GEOLOGY

The ore is situated in the Seve zone of the fjell. The ore is formed as a cup, steeping down towards a point below the top of Åreskutan.
The ore is very pronounced stratigraphic and could be follower as cm thick bands for kilometers of lenght. The main ore is located in three zones of crystallized limestone right below a calcite rich quartzic gneiss.
Bjelkes mine is associated to the top zone, then comes Fröå together with a number of small occurances in the middle zone. In the bottom zone lies some small occurances as Fäviken and Helgesjövallen.
The three ore containing zones belongs to Ordovicium, below the Seveskolla.

VISITS

99-07-?? : My first visit to Fröå copper mine was on invitation from Jämtlands amatörgeologer. As the interest from the other members in our society got colder and colder as closer to the trip date we came, I was the only one that travelled to Östersund that weekend.
I took the bus to Östersund, about six hours ride and was greeted by Lilian Jakobsson when I arrived.
After a long night with hot sandwiches, a lot of minerals and a few hours of sleep we packed our stuff in her car. The weather was fair and it promised a good day. On the way to Åre we joined the rest of the company.
In Mattmar (I could be wrong here) we made a short stop to pick up Börje Sellberg. I got a present from Börje, natrolite and stilbite from Fröå, and we also traded some minerals (I got an anatase from Åreskutan in exchange for some epidote).
When we reached the mine the sun was shining from a blue sky. It was just to start digging in among the boulders. It didn't take long before we started to find beautiful bornite and some other minerals.
After some hours (I think I lost track of the time) it was time for lunch. That was also a perfect time to pass out some minerals I had brought along as gifts.
After the lunch we decided to go down to Huså and visit the stone shop. After some phoning a man appeared and unlocked the shop. Everyone went inside to browse through the shelfs. In the attic there was a big collection on display. A collection donated by one of the members in Jämtland.
I made a few purchases (Spinel, chrysoberyl, glaucodot). After being told some local stories about the area it was time to go back home after a good day on the rim of Åreskutan.

LITTERATURE

Personal communications with Börje Sellberg. Mineral list.
SGU C89, pg 7
Wilke (1997), Mineralfundstellen in Schweden, pg 141.
P H Lundegård, Malm i Sverige 2, ISBN 91-20-03191-2, pg 60-62.

Mineral assemblage

Malachite, azurite, chalcopyrite, magnetite, covelline, bornite, pyrite, molybdenite, sphalerite, titanite, cuprite, hornblende, epidote, wollastonite, serpentine, chlorite, sillimanite, kyanite, quartz, feldspar, calcite.
And the famous zeolites :
Apophylite, stilbite, chabasite, natrolite, skolezite, tomsonite, harmotom, philipsite, heulandite, laumontite, mesolite.
Fröåite (is it a valid mineral?) only on quartz crystals.

Bornite
A nice specimen of dark colored bornite in quartzfilled veins in a finegrained quartsitic rock.
Collected in the summer of 1999

Natrolite
Small bursts of natrolite needles. Most of them are damaged, but some groupes are pretty good. The crystals are thin and fragile.
Matrix.
I got it as a gift from Börje Sehlberg, Östersund
(300 dpi, 800x600, k)

If you have some questions, suggestions or comments you are welcome to write me a line or two.

Locality index. Main index.

axelsson@acc.umu.se

	Bornite A nice specimen of dark colored bornite in quartzfilled veins in a finegrained quartsitic rock. Collected in the summer of 1999
	Natrolite Small bursts of natrolite needles. Most of them are damaged, but some groupes are pretty good. The crystals are thin and fragile. Matrix. I got it as a gift from Börje Sehlberg, Östersund (300 dpi, 800x600, k)