North Sea shells are (crops) used for all kinds of different applications, because they have some very useful and unique properties. Firstly, shells have a low specific weight. In addition, they have good water permeability. They also have a thermal insulating effect and they contain a lot of calcite. For these reasons, washed North Sea shells are often used as a lightweight foundation or as insulation in crawl spaces and other areas with moisture and mold problems. But they are also used to make shell paths in parks and forests.Properties• Stone type: Calcite• Hardness: Low• Color: beige / gray• Specific weight: ± 800kg / m3• Special features: Very low specific weight! Can come with BSB certification• Gravel plate or root cloth available as an option.+ Retaining straps and edge closures available as options.