Diatomite is a kind of siliceous rock of biological causes, mainly consists of remains of ancient diatoms. Diatomite is widely used as insulation, soundproof material due to it is the poor conductor of heat, sound and electricity.

General physical properties of diatomite:

1: light yellow or light grey, white

2: soft, low density

3: porous

4: strong water absorption

The main chemical component of diatomite is SiO₂, with small amount of  Al₂O_3,  Fe₂O_3,  CaO and MgO, etc.