Glossary [10]
graphite: mineral of grey colour which composes a part of marble. The amount of graphite in marble affects its colour.
ground surface: surface, which through appropriate treatments has been thinned, refined and smoothened. This technique is performed for example on terracotta.
hardness: resistence of some materials to the effect of mechanical forces like scratching, corrosion etc. Granite is a stone which is distinguished for its hardness, and for this reason it is widely used in the creation of outdoor paving that is mostly exposed to falling water, snow and sharp changes in temperature.
holocrystalline granular structure: typical structure of some rocks like granite composed of granules and characterised by the exclusive presence of crystals without the presence of any vitreous part.
impermeability: ability of some materials not to absorb water and other fluids. The impermeable materials like for example resins and stoneware, are highly suited to tile and floor covering.
