Introduction: The Serizzo, geological and cultural heritage of the Alps

In the heart of the Alps, between the Ossola valleys and the mountains that separate Italy and Switzerland, a stone that has literally built the architectural history of northern Italy and beyond has been quarried for centuries: Serizzo. This metamorphic rock, technically classified as paragneiss, represents not only a building material of exceptional quality, but a true cultural heritage that combines millennia-old tradition and contemporary innovation.
With its unique characteristics of strength and versatility, Serizzo from Ossola has found use in monumental works-from the base of Milan Cathedral to the pavements of major European cities-and continues today to be the preferred choice for road paving, curbs and street furniture from metropolises to small towns, from Italy to Switzerland. Its ability to withstand the most extreme weather conditions, combined with a natural aesthetic that fits into any architectural context, makes it an irreplaceable material for projects that require durability and beauty.
EuroSerizzi, headquartered in Villadossola in the heart of the mining area, is now one of the main points of reference for the supply of Serizzo and other natural stones, serving construction companies and public administrations throughout Italy and neighboring Switzerland.

Millennial history: from the Ossola quarries to the great Cities

The geological origins of the Serizzo

Serizzo was formed through a metamorphic process that lasted millions of years, when ancient sedimentary rocks were subjected to temperatures between 500 and 700°C and pressures of 3-10 bar, at a depth of about 7 km. This process gave the stone its characteristic schist structure and exceptional mechanical properties that make it ideal for use in construction.

The Golden Age of Mining

Serizzo quarrying in the Ossola valleys has ancient roots. Already in Roman times, this stone was used for the construction of roads and fortifications. In the Middle Ages, Serizzo knew a great diffusion: it was chosen to make the external base of Milan Cathedral, where we can still admire its resistance after centuries of exposure to the elements, while the upper part of the cathedral was made with pink Candoglia marble.

Serizzo in the industrial and modern era

With industrialization, the extraction and processing of Serizzo experienced a real revolution. The quarries of the Upper Ossola Valley, particularly in the Antigorio Valley and Formazza Valley, became centers of excellence for the extraction of prized varieties such as Serizzo Antigorio and Serizzo Formazza.
Since the 19th century, Serizzo has become a protagonist in major urban transformations:

• Milan: paving of historic squares and curbs of major thoroughfares
• Turin: street furniture in the historic center
• Swiss cities: from Lugano to Bellinzona, by squares and shopping streets.
• Contemporary projects: from Malpensa airport to new urban squares

Unique technical characteristics of Serizzo Antigorio

Mineralogical composition

Serizzo is composed mainly of:

• Quartz: gives hardness and abrasion resistance
• Dark biotite: defines the characteristic leafy texture
• White feldspar: contributes to mechanical strength
• Muscovite: unique sparkling mineral that gives natural shine

This unique composition creates a lamellar structure that facilitates natural splitting according to preferential planes (schistosity), allowing for slabs of uniform thickness that are ideal for flooring and cladding.

Physical-mechanical properties

The outstanding technical features of the Serizzo include:

Compressive strength: 1200-1800 kg/cm²

• Superior to most natural stones
• Ideal for pavements subject to heavy urban traffic

Wear resistance: abrasion coefficient <0.5 mm

• Provides exceptional durability over time
• Minimal maintenance required even in high-traffic areas

Frost resistance: over 150 freeze/thaw cycles

• Perfect for every climate, from the Alps to the plains
• Resistant to deicing salts used in the city

Water absorption: <0.3%

• Practically waterproof
• Ideal for areas subject to heavy rainfall

Color and aesthetic varieties

Serizzo dell’Ossola has a color range from light to dark gray, with possible veining and inclusions that make each piece unique. The main commercial varieties are:

• Serizzo Antigorio Chiaro: pearl gray shade, perfect for elegant and modern rooms
• Serizzo Antigorio Scuro: anthracite gray, ideal for architectural contrasts
• Serizzo Formazza: with more pronounced grain, suitable for both rustic and contemporary settings

Modern applications: curbs, paving and street furniture

Road curbs in Serizzo: Excellence for infrastructure

Serizzo curbs represent one of the most popular and appreciated applications of this stone, from major city arteries to historic centers. Their production follows strict standards that include a typical height of 20-25 cm, which can be customized according to design requirements, with running lengths or to specific sizes. The head, i.e., the upper surface, is worked with different techniques-bush-hammering, flaming or brushing-depending on the architectural context and functional requirements. The sides must be perfectly squared for at least 15 cm to ensure flawless alignment during installation.

The choice of Serizzo curbs provides superior resistance to impact and heavy vehicular traffic, while maintaining exceptional dimensional stability even under extreme temperature ranges. This feature is particularly valued in cities in northern Italy and Switzerland, where temperatures can vary by more than 40°C between summer and winter. The ease of installation and the perfect alignment achievable make Serizzo the preferred choice of many designers, while its compatibility with all types of paving-from asphalt to porphyry-makes it a versatile element for any urban context. With a lifespan that exceeds 50 years even under heavy use, Serizzo curbs represent a long-term investment for public administrations.

Urban and suburban pavements

Serizzo paving has won a prominent role in contemporary urban redevelopment projects. In monumental squares, this stone integrates harmoniously with both historic architecture and modern interventions, creating an aesthetic continuity that enhances the entire context. Commercial pedestrian areas benefit from Serizzo’s natural non-slip surface, which ensures safety even in rainy conditions, while its resistance to wear and tear maintains its original appearance despite the daily passage of thousands of people.

In city sidewalks, Serizzo provides comfort and safety for pedestrians, with a surface that remains stable and free of depressions even after decades of use. Public parking lots represent another area where this stone demonstrates its superiority: resistance to vehicular traffic combines with impermeability to motor oils and fuels, maintaining a decent appearance without requiring specific protective treatments.

The main types of processing available are:

• Saw plane: smooth surface ideal for minimalist and contemporary design
• Flaming: heat treatment that imparts outdoor anti-slip properties
• Bush-hammering: traditional finish perfect for historic centers and rustic settings
• Natural splitting: maintains the authentic appearance of stone for natural settings

In the residential and private sector, Serizzo finds application in driveways and courtyards where elegance goes hand in hand with the convenience of minimal maintenance, often combined with porphyry cubes to create unique decorative patterns. Pool edges benefit from the naturally non-slip surface that, unlike other materials, does not become slippery with water. Terraces and patios use Serizzo to create aesthetic continuity between indoor and outdoor spaces, taking advantage of the ability to achieve different finishes from the same base stone.

Innovative street furniture

Serizzo has evolved from a simple paving material to a leading player in contemporary street furniture. Bollards and bollards made of Serizzo offer elegant protection of pedestrian spaces, stylishly replacing traditional metal barriers. Steps and staircases, both monumental and service, take advantage of the material’s resistance to wear and tear to ensure safety and durability even in the presence of intense pedestrian traffic.

One particularly popular application involves gutters integrated into the pavement: Serizzo allows for drainage systems that do not interrupt the aesthetic harmony of the surface, while maintaining full hydraulic functionality. In traffic circles and traffic islands, this stone offers resistance to accidental vehicle impacts and optimal visibility thanks to the different surface finishes available.

On the decorative front, urban fountains made of Serizzo take advantage of the material’s natural impermeability to create durable, low-maintenance water features. Benches and seats combine ergonomic design and durability, resisting vandalism and weathering without losing their original appearance. Planters and raised beds elegantly delineate urban green spaces, while the material’s versatility allows artists to create installations and sculptures that enrich the urban landscape with permanent public art elements.

This evolution of Serizzo from a purely functional material to an urban design element testifies to its ability to adapt to contemporary needs, while keeping intact the technical characteristics that have made it irreplaceable in traditional construction.

An increasingly popular application involves the integration of Serizzo with metal gabions for innovative containment solutions that combine structural strength and contemporary aesthetics. In addition, Serizzo combines perfectly with cliff boulders for naturalistic engineering and landscaping works.

The Serizzo, a valuable choice for the future

Ossola Serizzo represents more than just a building material-it is an investment in the future of our cities and urban spaces. The combination of exceptional durability, timeless beauty and environmental sustainability makes it the ideal choice for projects that look far into the future.
Whether upgrading a historic plaza, creating a new pedestrian area or simply renovating the curbs of a street, Serizzo guarantees results that will last generations, while maintaining their functionality and aesthetics.

EuroSerizzi offers a wide range of natural stones in addition to Serizzo, including Gray Beola, Montorfano White Granite, Luserna, and Pink Granite, allowing designers to combine different materials for creative and functional solutions.