Homogenous sandstone with a cement or matrix of calcium carbonate which binds together the quartz particles of which sandstone is mainly composed. It splits almost equally well in both directions and is easily worked but disintegrates upon exposure. Pure calcareous sandstone is white or cream in color; colors are due to impurities: yellow and red colors are due to the presence of iron oxides; green from glauconite; and black from manganese dioxide.
