DESCRIPTION
Ylämaa is a small village about 30 km ssw from Lappeenranta.
During the second world war the Finnish was building fortifications along the
border to the Soviet union. When they blasted the rock they discovered that it
contained a very beautiful labradorite. It was later named to spectrolite.
That discovery started the quarrying of spectrolite in the area and is the base
of a local rock industry. Spectrolite is quarried for ornamental purposes
and for jewellery. A lot of it is processed locally and most workshops have their
own quarry.
The spectrolite quarries lies about 6 km sw of Ylämaa. There are a number of
quarries, but I don't know how many.
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GEOLOGY
The geology is really simple. The area consists of mainly rapakivi granites. In
an area near the lake Ylijärvi the granite is very coarse and of the labradorite
type. Crystals could reach sizes of up to 2 dm but most commonly is 3-5 cm. Many
crystals displays a number of colored zones depending on an optical phenomenon.
(Interference between alternating layers of albite and anorthosite creates the zones
and the thickness affects the colour.)
The rock looks dark because of microscopic inclusions of basic minerals as horblende
and biotite.
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VISITS
1997-06-27 On the day when we visited the quarry the sun was shining and
it was very warm.
I brought two large bottles of water and it was needed. We drove from Ylämaa
along a curvy, narrow dirt road. After a couple of km we turned up onto a forest
road that took us out in a typical Scandinavian forest. Mixed pines and spruces
and very dry on the ground.
We parked at a fork in the road where an even smaller road lead off to the quarry
200 m further up.
When we came to the quarry I was surprised. It was so small! It was just two
meters deep and 20x15m (if my memory don't fail me). Two thirds of the bottom
was full of water and the sides were very steep. It was possible with a little
climbing to go around at the waters edge. On one of the walls there were a hugh
spectrolite crystal, 20 cm across and shining in a very deep blue color.
We digged around in the gravel and picked rocks and pieces, cleaning them in
the water and selecting the best pieces.
When someone got enough they left and finally it was only me and two
Norwegians left, then we discovered that if we took water in the bottles and
splashed it at the rock heaps around the quarry it lit up in all possible colours.
In five minutes we found more spectrolite than during the previous two hours!
Finally even we got enough and we loaded the rocks in the car and left.
A real nice finale of our mineral journey and my first journey with the club.
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LITTERATURE
Mineralfundstellen-4 Skandinavien
Dr. H.-J. Wilke 1976
Christian Weise Verlag, München
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RELATED LINKS
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Mineral assemblage
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