Knowledge atlas
Nature
Clay from Liješeva, fine-grained, coherent soil
Clay is a sediment of very small colloidal particles, composed of various minerals, among which kaolin predominates. If it is wet, the clay is plastic and waterproof. It serves as a raw material for making pottery and porcelain goods, bricks and more.
- Name of Material in the local and Latin language
- Glina (Lat. lutum)
- Type of Material
- Mineral
- Commonly Found Locations
- Most clay minerals form where rocks are in contact with water, air, or steam - Liješeva, Visoko.
- Colour
- Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide.
- Density
- A fine and well-structured clay soil has a typical gross density 1 300 kg/m³.
- Hardness
- Clay absorbs water and becomes soft. Generally, in absence of water clay is hard like a solid whereas after absorbing water it becomes semi-solid. In all cases, it is a type of soil and therefore is solid.
- Solubility
- Clay is insoluble in water, but vinegar can dissolve clay to some extent.
- Structure
- The atomic structure of the clay minerals consists of two basic units, an octahedral sheet and a tetrahedral sheet. The octahedral sheet is comprised of closely packed oxygen's and hydroxyls in which aluminium, iron, and magnesium atoms are arranged in octahedral coordination.
- Chemical Composition
- Al2O3 2SiO2 2H2O
- Industrial and Crafts Applications
- Construction (brick, tile, sewer pipe, cement, fiberglass, roof granules, paint, etc.), manufacturing (refractories, kiln furniture, sanitary ware pottery and dinnerware), calcined form (fillers, carriers, extenders and grogs), ceramic industry (porcelain, fine ceramics, coarse ceramics).
- Historical or Cultural Uses
- Pottery, construction material
- Environmental Impact
- Terracotta and clay products are derived from natural earth materials, making them inherently sustainable. The extraction and processing of clay require minimal energy and resources compared to many other construction materials, such as concrete and steel.
- Extraction Methods
- Open-pit mining
- Processing Techniques
- Crushing, grinding, and screening, soaking in water, adding sand, mixing
- Sustainability and Environmental Considerations
- As clay is an organically occurring material, its extraction and use do not release volatile organic compounds, radon gas, or other toxins into the environment. The manufacturing process of ceramics such as clay bricks is similarly organic and non-toxic, with no need for chemical additives or preservatives. Clay as a building material is the most eco-friendly available on earth.
- Recycling and Waste Management
- Due to its natural origin and its components, clay is not only a sustainable material but also easy to recycle. Extracting clay from the soil is a process that has minimal impact on our environment. Combined with eco-friendly industrial practices, this makes clay one of the most harmless raw materials.
