Sandstone is a coarse grained sedimentary rock composed of small grains cemented by siliceous, felspathic, or calcareous cementing material. Sandstone is formed by the consolidation and aggregation of sand and held together by a natural cement, such as silica.
The cementing material determines the durability and color of the rock. It is mostly available in reddish, white, grayish or yellowish colors. Sandstone has varied applications as building stones.
Sandstone Physical Properties
The physical properties of sandstone are :
- Water Absorption: The capacity of water absorption is not more than 1.0%.
- Hardness: Lies between 6 to 7 on Moh's Scale Density 2.32 to 2.42 Kg/m3
- Color: Sandstone is available in many colors – red, green, yellow, pink, gray and white. The reason for the variation in colors being the change in the percentage of constituent and the binding material.
- Porosity: The porosity of sandstone is almost negligible. Thus sandstone is almost impermeable.
- Compressive Strength: Varies from 365 to 460 Kg/m2
Sandstone Composition
 Sandstone, the sedimentary rock is composed of small grains that are cemented by siliceous, felspathic, or calcareous cementing material. The cementing material determines the durability of the sandstone. This coarse-grained sedimentary rock is formed by the consolidation and aggregation of sand and held together by a natural cement, such as silica. The sandstone comprises of :
- Quartz grains
- Feldspar grains
- Rock fragment grains
It is the percentage composition of these components, that brings about variation in color and pattern of different types of sandstone
Sandstone Chemical Properties
 The compositon of sandstone is quite similar to that of sand, that essentially consists of quartz. The natural cementing material which binds the sand together as rock is usually composed of silica, calcium carbonate, or iron oxide. The percentage constitution of each constituent varies between certain limit, which is as follows:
| SiO2 |
93-94% |
| Alumina(Al 2O 3) |
1.4 to 1.5% |
| Iron(Fe2 O3 ) |
1.5%-1.6% |
| Lime(CaO) |
0.8% to 0.9% |
| Soda(Na2 O) & Potash (Kro) |
1.0% to 1.2% |
| Loss On Ignition(LOI) |
1.0% to 1.2% |
| Magnesia(MgO) |
0.2 to 0.25% |
They are highly resistant to acids, alkalis and thermal impact and their insolubility in acids and alkalis is about 97%
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