Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor composed of a plurality of similar covering or lining elements, stone or stone-like materials, e.g. ceramics {concrete,}; of glass {or with an outer layer of stone or stone-like materials or glass with an outer layer imitating natural stone, brick work or the like}