Expanded minerals

Expanded minerals can be used as loose-fill insulation material in cavities, or as levelling fill (e.g. for dry screeds).

Expanded perlite is available as panels, which can also be used where considerable pressure is involved (e.g. floors). Expanded mica is also used as an additive in building materials such as plaster, in order to prevent cracks forming due to temperature fluctuations. Bonded with cement, expanded clay is used as material for masonry; it is also an additive in lightweight concrete, mortar and clay.

Expanded clay (source: Lucis 2007, http://en.wikipedia.org/wiki/File:Hydroton.jpg)