Fluffy type of insulation, used prior to the invention of insulation, it is created by subjecting rock or molten refuse from the melting of metals or ores to high-pressure steam blasts.
Mineral wool, means fibres made from minerals or metal oxides, be they synthetic or natural. In industry use, MMMF (man-made-mineral-fibres) generally refer to synthetic materials. This includes fibreglass, ceramic fibres and also rockwool, also known as stone wool, and rock wool.