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Our material is 100% mineral. Our no-firing process allows to solidify marine sediments and mold them into the desired shape.

Our creations can be dyed in the mass thanks to natural pigments. 

Our innovation

The process developed by GWILEN exploits the intrinsic properties of marine sediments and allows them to solidify to the desired shape without cooking. This process is inspired by diagenesis, which is the natural process that transforms sediments into rock. Being inspired by Nature is indeed the best way to design in harmony with it.

An ecological material

GWILEN meets two major environmental needs: to reduce the environmental impact of the construction sector through its materials, and to manage port dredging sediments.

Our innovative solution addresses the two aspects that make the construction industry polluting.

The energy

Our process does not require high-temperature firing, which considerably reduces energy consumption during production, and therefore the embodied energy associated with our material. It generates 4 to 5 times less CO2 emissions than the production of a terracotta which is already 3 times less emitting than concrete (Life Cycle Assessment on CO2 emission conducted in 2021).

We innovate by valorizing marine sediments which currently have no valorization channel to absorb the extracted volumes. Thanks to its process, GWILEN valorizes resources that are already available to us all along the French coastline, but also all over the world, since silting is a physical problem and physics has no borders: all ports silt up.

The resources

Our ecological and innovative material is derived from already available and currently unexploited resources, harbor sediments, which we transform in our Brest workshop. Our mineral and marine material is unprecedented in the design and construction market: it offers a new aesthetic while providing a breakthrough solution that meets recent regulatory constraints (RE2020).

GWILEN on France 3 Bretagne to talk about the valorisation of marine sediments:

La version longue du reportage est accessible ici.

To learn more about the ecological aspect of our material, visit our Project page!

Material properties


The material we produce has a unique texture. Between a terracotta and a concrete, it has in some aspects similarities with stone. The process used to solidify it is inspired by diagenesis, the natural process of formation of sedimentary rocks. Sometimes it looks like a sedimentary rock. Sometimes, it even seems aged, like an ancient tile that has already lived.

It is a material of marine origin 100% mineral. We do not add cement or resin.

All our pieces are handmade in our workshop in Brest, France, through an artisanal manufacturing process. Our material is natural and comes from a resource that has variability. Thus, the appearance and color may vary slightly from one piece to another, making each one unique. Far from trying to standardize this, we believe that this is the guarantee of authenticity and a simple relationship with natural materials and their richness. Like leather or natural wood, it is a material that lives, interacts with its environment and must be cared for, to allow time to give it a patina making it more beautiful every day.


Our material can be molded, so it can take many forms, depending on the application for which the object is intended. 


The natural color of our material is a sandy beige color. This color may vary slightly depending on the origin of the sediments we use, which do not all have the same exact properties. 

We can color our material. We use natural pigments, directly added to the material during the casting process. It is thus tinted in the mass which gives it this so particular depth. We can make it take a wide range of colors, looking for a rather uniform shade that will always present the intrinsic variations of the material, or voluntarily mix several shades, which can create effects of marbling or effects of gradations by playing on the intensity of colors.

We have defined a range of colors that you can find on our color chart, but we also develop specific shades for custom projects. Discover a selection of our projects here.

Prototypes et explorations

The Merrazzo

GWILEN developed a new version of its material, the Merrazzo, at the end of 2021. The Merrazzo is a marine terrazzo, obtained by adding shell fragments to our sedimentary material. In this way, we are not only recovering dredged sediments, but also shellfish waste.

La première application de ce nouveau matériau a été le développement de plateaux en différentes tailles, proposés avec des éclats de coquilles d’huîtres, de moules ou de coquilles Saint-Jacques. 

En nous intéressant à cette autre ressource, nous nous rendons alors compte qu’elle possède déjà de nombreuse applications : agroalimentaire, agriculture, cosmétique. Des applications utilisant les propriétés de la coquille. Les intégrer dans notre matrice sédimentaire revenait à les encapsuler plus que les valoriser. Un vraie perte de valeur à l’heure où il faut utiliser nos ressources, même issues de valorisation, avec parcimonie.

En parralèle de cela, notre production augmentait, et inévitablement, lors des tri et casses de production, nous accumulions des rebus de production. Nous avons alors lancé des essais afin d’intégrer ces rebus à notre matrice, pour créer une nouvelle version de notre Merrazzo, toujours 100% marine et cette fois, 100% cohérente avec notre démarche.

Retrouvez ci-dessous notre plaquette commerciale et dossier de presse, et prenez rendez-vous avez nous afin d’échanger sur nos produits et vos projets !

Téléchargez aussi notre fiche technique (murs et sols), ou commandez des échantillons.