Sandstone is a sedimentary rock formed under oceans, lakes and rivers, where sand is laid down and buried. It is composed of cemented sand grains, rock fragments, minerals and organic material. The cementing material that binds sand grains together and occupies spaces between them is typically silica and calcium carbonate, which are often derived either from dissolution or from alteration of the sand after it was buried. Sandstone colour is usually yellow, red, brown or grey to white reflecting the variation in mineral content and cement. Sandstone can be softer to harder, depending on clast and cement composition. The more calcium carbonate it contains, the harder and more resistant to weathering it is. Sandstone containing lots of quartz is recognised for its natural strength, durability and slip-resistant properties. One of the best examples of architecture using sandstone is the city of Petra.
- Porous, absorbs water
- Hardness on the Mohs scale 5.5-7
- Moderately resistant to weathering
- 4. More sensitive than granite
- High humidity can cause colour change
- Not scratch resistant
- Requires sealing
What is sandstone used for?
- Kitchen worktops
- Bathroom vanities
- Interior and exterior walls
- Pool decoration
- Fireplace surrounds
- Window niches