Scandinavia : land of the larvikite
Blue Pearl granite (larvikite) may be the best known stone from Scandinavia, but the region has a lot more to offer
The first thought that comes to most people’s minds when they think about Scandinavian stone is labradorite (or larvikite) – the Pearls. But it is not only Blue Pearl that comes from Scandinavia.
Hard landscaping specialists CED, based in Grays, Essex, and offering national coverage from their various depots, like to convince designers to use something more interesting than grey granite. And among the products they offer are quartzites and a phylite, as well as granite, from Norway and Sweden.
Favourite of CED Managing Director Michael Heap among the Scandinavian products is Alta quartzite, with a slight greenish tone and a pale silvery mica sheen along the riven surfaces. It comes from one of Norway’s major stone companies, Minera Norge AS.
Alta quartzite has been used all over the world, from the USA and Europe in the West to Japan in the East. It can be seen at the Louvre, Paris, and Paseo Maritimo, Barcelona, as well as in the Urbis Centre in Manchester where it has been used for both the external paving and internal flooring.
Another of Minera’s materials is Oppdal quartzite. Michael says it is not quite as amazing as Alta, but it has the ability to be cut like glass to varied shapes with straight or curved edges. As a result it forms superb cropped walling.
Minera Norge’s quartzites and phyllites are metamorphic, having been substantially altered since their original sedimentary deposition as quartz sand 600-750million years ago.
According to Minera, their materials are “quite out of the ordinary with bending strengths far exceeding those of a typical granite.” The flextural strength is one of the attractions of Alta to Michael Heap.
He also likes the fact that it can be naturally riven, is slip resistant and available in lengths that can be three or four times the 300-400mm widths.
It adheres readily to mortar, making it possible to lay a thin flag (20-30mm) in trafficked locations. It is both frost and acid resistant and inhospitable to algal, fungal and moss growth (which is why quartzite has been used for swimming pools all over the world). “Alta is one of the top materials, inside and out,” says Michael.
He adds: “There are qualities available from Scandinavian stones which are quite different from anything else. There are some niche and very interesting materials that can be utilised in design. And we are not talking about the prices of Emerald Pearl. Most of them are less than £100/m2, often less than £70. They definitely have their place in technical terms and aesthetic terms.”
Minera extract quartzite from three locations. Alta in the far north, Oppdal in central Norway and Offerdal in Sweden, while phyllite is quarried at Otta in central Norway. All these products are supplied in the UK by CED.
Norway also produces soapstone (steatite), which has been used as a building material in the country for centuries. Trondheim Cathedral is a good example that dates from the Medieval. Stavanger Cathedral, St Mary’s, the Church of the Holy Cross and the Cathedral in Bergen also bear witness to the long-term durability of this stone best known in the UK for its ease of use for decorative carving.
Currently dimension or decorative stone is extracted from about 80 quarries in Norway. Blocks of larvikite from around 20 quarries account for almost 80% of the export value. Schist and flagstone, granite and marble are also produced. Two deposits of exclusive stone came into production a few years ago: Labrador Antique anorthosite (brown with a blue play of colour) from south-west Norway and the Emerald Green Masi Quartzite from northern Norway.
There is also Norwegian Rose, an internationally renowned marble. It is quarried at a site 60km north of the Arctic Circle at Fauske near the city of Bodo. The annual production is around 500m3. Blocks ranging from 1.4 to 13tonnes are extracted. Density is said to be 2,717kg/m3 and porosity a mere 0.3%. Monuments are the principal end use. Lundhs are the leading exporters of Norwegian Rose today (www.lundhs.no).
Norway is the most important producer of dimension / decorative stone in Scandinavia, extracting more than 500,000tonnes a year worth about 600million Norewegian Krone (a Norwegian Krone now being worth about £1, although the stone is normally sold in Euros). More than 90% of sales come from exports.
Finland, which was variously ruled over by Sweden and Russia before gaining independence with the Russian revolution of 1917, has long been recognised internationally as a source of high quality granite and since 1980 has enjoyed a renaissance in soapstone quarrying.
Soapstone is used, among other things, to make woodburning stoves that are gaining in popularity in many parts of the world as oil and gas prices rise.
Balmoral Red and Kuru Grey granite come from south-west Finland while Baltic Brown and Carmen Red come from the south-east. Colours of Finnish granites include red, brown, grey, green, yellow and black. Today, there remain about 60 quarries active out of a total of around 100.
Granite quarrying in the south-east has a history going back at least 300 years. Finns are proud of the fact that a single monolith of dark-red rapakivi granite extracted at Pyterlahti in the Virolahti district of their country was used to create what is believed to be the tallest monumental column in the world at 47.5m high. It is still standing on Palace Square facing the famous Winter Palace in St Petersburg, Russia.
But in spite of the various stones available from Scandinavia, probably the most famous remain the Pearls, or Labradore granites, which are largely larvikites. Some examples are pictured on this page. They come from stone wholesalers Brachot-Hermant, whose UK branch is in Birmingham and who operate their own larvikite quarry (pictured left).
So when is a labradorite a larvikite? Labradorite is a variety of plagioclase feldspar that has been quarried for centuries in some parts of the world and derives its name from the region of Labrador in the province of Newfoundland, western Canada. Larvikite is only found in the vicinity of Larvik, south-eastern Norway. It is a variety of syenite called monzonite, which usually contains orthoclase rather than plagioclase. The large feldspar crystals at varying angles in the matrix produce the shimmering iridescence known as the ‘Schiller effect’.
Geologists believe the events responsible for the genesis of larvikite were unique to this area. Labrador Brown Pearl comes from a quarry near Hellvik, in the south-west of Norway, but geologically it is classified as anorthosite.
The larvikites mainly consist of feldspar minerals (mainly alkali-feldspar) that are often several millimetres large. Furthermore, dark (mafic minerals, such as augite, olivine, hemo-ilmenite, biotite and apatite) and accessory minerals occur. Geologically, these natural stones are subdivided as syenites.
The basic colour of the different labrador types is mainly determined by the colour of the feldspars and the quantity of dark (mafic) minerals. The colour of the feldspars varies from soft grey to dark grey and almost black. The origin of the colour of the minerals is based on the chemical-mineralogical composition of the natural stone. The feldspar minerals present a more or less clear orientation parallel to the cleavage plains in the crystals.
This is the usual cutting direction of the rock. When sawing in this direction, the most lengthwise diameter of the feldspar crystals can be obtained to create the most impressive Schiller effect. n
Acknowledgements
NSS acknowledges with thanks the contributions from which this report has been compiled:
1)Paul Daniel, who in turn wishes to record his gratitude to Tom Heldal (Tom.Heldal@NGU.no) of the Norwegian Geological Bureau.
2)CED for information about quartzite and phylite
3)Brachot-Hermant for the information about their labradorite and larvikite.