Serizzo

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Serizzo Antigorio , polished
(sample approx. 25 × 15 cm)
Valle Antigorio, old paved roads on the Toce near Crevoladossola

Serizzo (occasionally Sarizzo , Italian : pietra di serizzo ) is a handcrafted and internationally widespread group designation of stone from Italy. It finds its proper use for plate-split and sawn gneisses from the southern Alpine region. The best known example is the Serizzo Antigorio from the Valle Antigorio .

term

General

The term Serizzo is not a petrographic name. It comes from the old colloquial practice of artisanal stone processors in the Piedmont region . The word Serizzo , in its original usage form by the stone workers north of Crevoladossola , denotes orthogneiss . Information based on older sources denotes the natural stones obtained under the main name Serizzo as paragneiss .

In Italy, the addition of the name Serizzo and correspondingly Beola for split or sawn gneisses is common and accordingly widespread. In the Italian-influenced natural stone sector, the term Serizzo is also used as an addition to the trade names of ashlar stones that are similar to the gneiss from the Valle Antigorio and Valle Formazza in terms of their splitting and / or optical properties and do not necessarily have to come from Italy. In this sense, Serizzo can appear as part of the name in very variable contexts, such as the gneiss Onsernone (gneiss "serizzo", Sarizzo Onsernone ) or the gneiss Verzasca ( Serizzo Verzasca. ) In Ticino the term Serizzo is only marginally widespread.

Serizzo, Beola, Bevola and other alternative names

Traditionally rooted and parallel to the name Serizzo , the Italian suffix Beola is used for extractable gneiss or Bevola or Bevole in Ticino . As such, stones are called which, in the petrographic sense, are ortho or paragneiss, depending on where they were extracted. The distinguishing features of the traditionally coined terms Serizzo and Beola do not lie in geoscientific criteria with regard to their history, but in the practical experience of the extraction of these rocks over several centuries. As Beola or Bevola accordingly those gneisses, which can be obtained through their natural reservoir structures and using simple procedure in thin-plate pieces apply. In the Val d'Ossola near Beura-Cardezza as Beola Bianca or in Ticino, for example, as Bevole di Valle Maggia . In contrast to Serizzo , the collective term Beola or Bevola in the technical language of the processors denotes a group of easily split "slab gneisses ".

Serizzo or Sarizzo , on the other hand, refers to a gneiss that occurs in extensive fissures and can originally only be converted into processable raw blocks or slabs through increased manual and later mechanical effort. In this context, its traditional historical name Pietre Risse can be understood as an indication of this. The situation is similar with the recoverable gneiss from the Leventina Valley , which Quervain describes as "transitions from strong foliation to quite massive formation".

Gneiss quarry in the Maggia valley with narrow crevices and thus a clear platy form of the rock ( Bevole di Valle Maggia )
Gneiss and old architecture in the Valle Verzasca ( Ponte dei Salti )

Furthermore, the terms fission granite and Ticino gneiss are still used in Ticino . In terms of craftsmanship and technology, such rocks have obvious similarities with the Serizzo or Beola varieties. Split granite, incorrect in the petrographic sense because it is not granite, was also used in the natural stone sector for serizzo varieties from Italian mining regions. As a result, in this region, as in Ticino, trade names with the main name Granito can be found for gneiss .

Origin and location

Serizzo and Beola received their characteristic feature, the splittability as a result of the alpine mountain formation . The associated large deformation resulted in the parent material (usually granitoid rocks) to a cleavage which is connected to a Einregelung of minerals, can be easily split along which the rocks. The primary feature is the characteristic mica layers in the rock.

The Italian deposits and mining sites are located in the system of the Western Alps , more precisely in the Penninic area , in its middle and lower ceiling complexes . The orthogneiss of the Serizzo varieties come from the Antigorio ceiling. The Beola quarries are located in the orthogneiss of the Monte Leone Nappe, the Orselina-Moncucco-Isorno Zone and the Camughera Zone of the central Penninic nappe complex with the Centovalli Fault, the Monte Rosa Nappe and the Sesia-Lanzo -Zone of the Austroalpine north of the Canavese line .

Mineral composition

Serizzos are made of quartz , black biotite and white feldspar . In addition to these minerals, muscovite , the light-colored mica, also occurs every now and then as an individually glittering component. Since biotite, the dark mica, is distributed in planar parallel textures of the rock, these natural stones can be split evenly. If the Serizzo is sawn against the bed, an “ eye-gneiss-like ” structure usually arises because the black biotite has accumulated in radial crystal clusters around the quartz and feldspar deposits .

Occurrence

The gneisses, known as “Serizzo” in international trade, are extracted in the area around Crevoladossola , Crodo and Formazza , and also near Sondrio and in the canton of Ticino . For these regions, mining and processing are of great economic importance.

The tradition of quarrying has strongly shaped the appearance of regional architecture in the valleys of the Verbano-Cusio-Ossola province . Typical evidence of this are masonry, roofing and wells. The rocks have been supplied to other northern Italian regions for several centuries and have been exported extensively since the 20th century. Important mining regions are:

Beole (selection)

  • Val d'Ossola ( Beola Bianca ) between Beura and Crevoladossola and near Vogogna
  • Val di Antrona ( Beola Ghiandonata ) near Antronapiana
  • Val d'Ossola ( Beola Grigia ) between Beura and Crevoladossola
  • Val d'Ossola ( Beola Bianca Vogogna ) near Vogogna
  • Val d'Ossola ( Beola Favalle ) near Crevoladossola
  • Val d'Ossola ( Beola Argentata ) between Montecrestese and Crevoladossola
  • Val d'Ossola ( Beola Isorno ) between Montecrestese and Crevoladossola

Similar types of natural stone from Switzerland

The stone quarrying work in the Verzasca Valley is very old, during which fall blocks lying around for a long time were reclaimed.

Technical characteristics and use

Serizzos are frost-resistant and wear-resistant. They can be polished and flamed. Their uses are diverse in construction and interior design; they are used in Germany both indoors and outdoors, e.g. B. as stairs and floor coverings , facades , vanities and kitchen countertops . In the Italian-Swiss border area, for example, this rock is also used as a curb and building block.
The structurally attractive varieties are sold in the region and in export. Due to their visual characteristics, especially their color and texture, they are among the most extraordinary natural stones in Europe. That is why they are used, for example, for special facade and interior designs , design objects or fountain systems .

literature

  • Tarcisio Bullo: La belle epoque: tra illusioni, sfruttamento e lotte sindacali . In: Annuario alto ticino 2006, Claro 2005 pp. 9–12.
  • M. Catella, E. Corbella, C. Costa et al .: Marmi Italiani Guida Tecnica . Fratelli Vallardi Editori, Milan 1982.
  • Karlfried Fuchs: Natural stones from all over the world, discover, determine, use. Vol 1 . Munich Callwey, Munich 1997, ISBN 3-7667-1267-5 .

Web links

Serizzo quarry

Individual evidence

  1. ↑ a b Friedrich Müller: INSK compact . Ulm, sheet 48.2 Serizzo Antigorio.
  2. ^ Karlfried Fuchs: Natursteine , p. 114
  3. ↑ Günther Mehling (Ed.): Natural stone lexicon. Munich 1993, p. 508.
  4. ^ Günther Mehling: Natural stone lexicon. 1993, p. 405.
  5. ↑ an example of synonymous terms used .
  6. ↑ a b Onsernone granite. Quarries . on www.granito-onsernone.ch (Italian).
  7. ↑ Natural stone, The specialist portal: Onsernone . on www.natursteinonline.de .
  8. ↑ Natural stone, The specialist portal: Verzasca . on www.natursteinonline.de .
  9. ↑ F. de Quervain: The usable rocks of Switzerland . Kümmerly & Frei, Bern 1969, p. 83.
  10. ↑ Associazione Marmisti Lombardia: Nostri marmi sono la vostra storia. Beole . on www.assomarmistilombardia.it (Italian)
  11. ^ F. de Quervain: Rocks of Switzerland . 1969, p. 84.
  12. ^ Friedrich Müller, Reinhard Kögler: INSK compact . Ulm, sheet 46.6 Beola Bianca
  13. ↑ F. de Quervain: The relationships between usable rock deposits and the geological structure of the subsurface . In: Ernst Reinhard (ed.): Stone and stone work . Bern, Basel, Olten, 1945, p. 31.
  14. ↑ Laura Fiora: varities of "Serizzo" stone in the Alps . In: L'Informatore del Marmista. Giorgio Zusi editore, Verona, issue no.567, March 2009 (abstract English).
  15. ^ F. de Quervain: Rocks of Switzerland . 1969, p. 74.
  16. ^ F. de Quervain, M. Gschwind: The usable rocks of Switzerland . (Geotechnical Commission of the Swiss Natural Research Society) Bern 1934, p. 49 ff.
  17. ^ F. de Quervain: Rocks of Switzerland . 1969, p. 78.
  18. ^ Regione Piemonte: Pietre ornamentali del Piemonte . Instituto nazionale per il Commercio Estero, Turin 2000, pp. 26-28
  19. ↑ The Alpine structure and the layers . on www.pietredelvco.it (German).
  20. ↑ Peter Bearth: On the geology of the root zone east of the Ossola valley . In: Eclogae Geologicae Helvetiae. Vol. 49 (1956), issue 2 on www.E-Periodica.ch (German)
  21. ^ Toni P. Labhart: Geology of Switzerland . Otto Verlag, Thun 2001, ISBN 3-7225-6760-2 .
  22. ^ F. de Quervain: Rocks of Switzerland . 1969, p. 82.