Bluestone is rapidly growing in popularity, with this there is great confusion surrounding what Bluestone actually is. Bluestone is not a geological term, it does not fall under any one category such; Igneous, Sedimentary or Metamorphic. This is because it currently represents over 20 different rock types.
In the U.S. and Canada it is generally a type of Sandstone which is deep blue in colour, but in some parts of the US & Belgium it is a form of Limestone that has formed in deeper water and exposed to less light the stone eventually fades from a deep blue to a light grey after prolonged exposure to the sun.
In Australia there are two types, one commonly known as Victorian Bluestone which is a form of Basalt. Basalt is an igneous rock made up mainly of feldspar; it is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. In South Australia it is known as a form of Slate. Slate is a metamorphic rock which is mainly made up of quartz and is usually pale grey or beige in colour, it should be noted that it is much less durable than the Victorian Bluestone.
Chinese Bluestone is commonly a grey Limestone. Limestone is a sedimentary rock that largely made up of minerals calcite and aragonite, which are different crystal forms of calcium carbonate. Limestone is very porous and highly reactive to acid.
There are many types of Bluestone and they all need to be treated and cared for differently, they vary from very hard, durable and dense to very soft and porous. To help identify the type of Bluestone you have our intend on using it is important that you get as much information about the stone from the supplier as possible, information such as; place of origin (location of quarry), type of stone, porosity, any special laying procedures (pre-sealing prior to laying), whether it is acid sensitive etc. This is the best way to make sure you end up using the correct cleaning & sealing products, unfortunately the is no magic chemical that can fix or prevent any situation with stone, so it is important that you use the right chemical for the correct situation. Spirit Marble & Tile Care are experts on all natural stone & tile situations and any questions you have will be answer professional by one of our experienced applicators over the phone or via email.