Specification :

Cerium oxide, belonging to the group of elements known as the rare earths, occurs in nature in diverse forms. The two most commercially important are bastanite, which is a complex fluorocarbonate, and monazite, which is a phosphate. To produce the polishing powder, about 50% -100% of cerium oxide and balance of other rare earths oxide are used. When the polishing powder is applied to glass, it reacts with the surface to produce a complex cerium-oxygen-silicon compound softer than glass. This softer surface layer can then be more easily applied to produce the final polished surface. As polishing is the final step in the surfacing process, it should not be expected to remove errors made during previous steps when the shape is formed and smoothed. It is therefore necessary that both previous steps, bevelling and smoothing are done correctly and accurately.