Lainejaur

DESCRIPTION

Lainejaur lies about 12 km north of Malå. The mine is located east of the lake Lainejaur at the end of a small forest road.
The ore was discovered in 1941. Since nickel was an important metal and it was in short supply during the war, the mine was quickly opened and stood for a large part of the nickel needed in Sweden.
The mining operation was stopped at the end of the war. When it was closed in 1945, the mine contained two shafts and went down to a depth of 213m.
The mine was closed because of economic, so there are still ore in the bottom of the mine.
During it's short active time a total of 114000 tons of ore were mined.
There was a lot of material on the dump piles. Unfortunately most of the dump piles have been crushed to gravel and used for roads in the area. There are only a small amound of rocks left around the mine. Still it's possible to find nice samples of the ore minerals.

There are not a so much traces left from the buildings of the mine. Only a few concrete constructions remain. There is also the two mine shafts which are sealed off with thick timber platforms. The mine shafts itselves are only about 3-4 m across.

GEOLOGY

The ore differs from the other sulphide ores in the Skellefte district. The ore contains mainly pyrrhotite and pyrite only occurs as a rarity. The ore lies in a contact zone between gabbro and phyllite. The main nickel nickel ore concists of pentlandite bearing pyrrhotite. Around the main ore lies a lot of breccias and fissures containing nickel and cobalt sulphides as a late stage mineralisation.

VISITS

2000-08-06 Lainejaur lies about halfways between Umeå and Ultevis. It seemed as a good place to take a break so we planned to stop there for a few hours on our journey to Ultevis. When we got there, some people started to take out coffee. Not me, I picked my hammer and went on a quick stroll around the area. Without any backpack you can't take so much rocks with you back to the cars. Well I swept the area and when I got back to the car I was carrying as much I could in my hands!
Even though the dump piles was mostly gone we all found nice samples of nickeline, gersdorffite and annabergite during the next hour.
After a while Sven-Erik came and announced that the lunch was served. It has it's merits to bring someone that's not interested in minerals on our journey. When we had eaten our lunch we decided to leave in fifteen minutes. OK, I thought, one last quick walk around the area then, looking at the mineshafts and the buildings.
When I came to the mineshafts, a larger rock caught my eye. I digged it out. It was rusty, about 25 cm and almost round. I brought it back to the car and gave it a good hit with the sledgehammer. It cracked straight through the middle. It was full of veins with nickeline. A nice ending of my first visit.

LITTERATURE

   Grip, E :
      Nickelförekomsten Lainijaur.
      GFF 64, 1942, pg 273

   Antti Hulterström, Västerbottens Amatörgeologer :
      Fyndortsbeskrivning Lainejaurgruvan, 1993.

Mineral assemblage

Annabergite, Apatite, Arsenopyrite, Augite, Biotite, Bornite, Bravoite, Calcite, Chalcopyrite, Chlorite, Clinozoisite, Cobaltite, Dolomite, Epidote, Galena, Garnet, Gersdorffite, Hornblende, Ilmenite, Loellingite, Magnetite, Maucherite, Microcline, Molybdenite, Nickeline, Nickel-skutterudite, Olivine, Pentlandite, Phlogopite, Plagioclase, Pyrite, Pyrrhotite, Quartz, Rammelsbergite, Rutile, Safflorite (probably gersdorffite), Scheelite, Sericite, Serpentine, Skutterudite (Smaltite), Sphalerite, Spinel, Taenite, Talc, Titanite, Tourmaline, Valleriite, Zircon.

Gersdorffite
Half of this rock contains gersdorffite. It is almost pure, there are only some traces of nickeline and pyrrhotine.
It comes from a vein running through a rock. The host material is hard to identify, it is made up of some dark rock, probable gabbro.
Collected in 2000-08-06
(Size 4x3x2 cm)

Nickeline
A nice example of the occurance of nickeline.
A fissure filled with gersdorffite, nickeline and chalcopyrite. there is no crystal forms visible. The nickeline makes up the core of the fissure, the part that lies directly against the surrounding rock is made up of gersdorffite. There are also a sharp thin rim of yellow chalcopyrite on the lower side between the gersdorffite and the rock.
Collected in 2000-08-06
(Size 8x5x5 cm)

Annabergite
A vein of gersdorffite is covered with annabergite.
The surface is damaged in the middle, showing the gersdorffite below.
As a gift from Mikael Jansson.
(Size 5x2.5x2.5 cm)

Pentlandite
Grains of pentlandite is included in this rock. There are also a lot of pyrrhotite in this rock.
As a gift from Ingemar Johansson.
(Size 6x4x3 cm)

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

	Gersdorffite Half of this rock contains gersdorffite. It is almost pure, there are only some traces of nickeline and pyrrhotine. It comes from a vein running through a rock. The host material is hard to identify, it is made up of some dark rock, probable gabbro. Collected in 2000-08-06 (Size 4x3x2 cm)
	Nickeline A nice example of the occurance of nickeline. A fissure filled with gersdorffite, nickeline and chalcopyrite. there is no crystal forms visible. The nickeline makes up the core of the fissure, the part that lies directly against the surrounding rock is made up of gersdorffite. There are also a sharp thin rim of yellow chalcopyrite on the lower side between the gersdorffite and the rock. Collected in 2000-08-06 (Size 8x5x5 cm)
	Annabergite A vein of gersdorffite is covered with annabergite. The surface is damaged in the middle, showing the gersdorffite below. As a gift from Mikael Jansson. (Size 5x2.5x2.5 cm)
	Pentlandite Grains of pentlandite is included in this rock. There are also a lot of pyrrhotite in this rock. As a gift from Ingemar Johansson. (Size 6x4x3 cm)