PERLITE
	Typical analysis of perlite   * 70-75% silicon dioxide: SiO2   * 12-15% aluminium oxide: Al2O3   * 3-4% sodium oxide: Na2O   * 3-5% potassium oxide: K2O   * 0.5-2% iron oxide: Fe2O3   * 0.2-0.7% magnesium oxide: MgO   * 0.5-1.5% calcium oxide: CaO   * 3-5% loss on ignition (chemical / combined water)