Clite 300S is a ceramic microsphere used in cementing applications.  Also known as cenospheres, these hollow ceramic spheres are a by-product of coal burning power plants.  When pulverized coal is burned at power plants fly ash is produced. Cenospheres are the lighter particles that are contained within the fly ash.

Most cenospheres are "harvested" or scooped up from ash ponds.  Some cenospheres are also collected at the power plants themselves.  These wet microspheres are than dried, processed, and packaged to meet customer requirements.

Cenospheres are not as strong as the A Series hollow glass microspheres.  Typically, cenospheres will start to breakdown at 2500-3000 psi.