Magnesian Limestone thin section microscope slide. This material belongs to the Zechstein Formation; a highly studied sedimentary formation which was laid down in the epeiric Zechstein Sea during the Mid to Late Permian Period. This material was sourced around Tadcaster in North Yorkshire and was deposited when the UK was situated at an equatorial latitude. This limestone contains high concentrations of the Magnesium rich mineral – dolomite CaMg(CO3)2. Some crystals may be brown as a result of weathering or iron stained due to the presence of iron oxides. The glass is 46 x 27 mm in size, supplied in a protective card sleeve with a label, ideal for microscopy, petrology & educational use.