Limestone and Sandstone
Limestone will frequently exhibit structures and other relic features that give clues to the age and environment that existed when the deposit was laid down.
Sandstones are another sedimentary rock type. The source of sandstones grains are those minerals and rock fragments that remain after weathering and erosion of previous rocks. As with limestone the presence of other minerals, rock particles, fossil traces and depositional structures all combine to influence the overall appearance of sandstone. The cement that bonds these grains together to form a stone is wide ranging. It can be siliceous, calcareous, ferruginous, carbonaceous etc. or various combinations of some or all. The nature of this cement naturally will have an effect on the colour of this material and will be one of the main factors governing its physical qualities of strength and porosity.
