Asbestos is a naturally forming mineral called Hydrous Magnesium Silicates. These were mainly mined and imported from Canada & South Africa.
It is estimated that approximately 5 million tonnes + were imported into the United Kingdom and used extensively in some 500,000 buildings.
This was mainly due to the materials excellent qualities for resistance to chemicals, high tensile strength, resistance to heat and flame, high insulating properties and flexibility which made it an ideal product in the construction industry. In many cases and products asbestos remains in a good condition for decades.

There are 3 main commonly known types of asbestos:

Chrysotile – commonly known as white asbestos. Used primarily in cement products and other various materials and papers.
Amosite – commonly known as brown asbestos. Typically used in pipe insulation and lagging applications or mixed with other materials to form asbestos insulation board (AIB).
Crocidolite – commonly known as blue asbestos. Typically used within sprayed coatings and insulation and referred to as the most dangerous of the three.

Although the asbestos types are commonly referred to by colour, this does not prove an ideal way to identify the material and microscopic investigation is recommended by the accredited surveyors/laboratories.