Beryllium Oxide, also known as beryllia, is an inorganic compound with the formula BeO. Beryllium oxide can be prepared by calcining beryllium carbonate, dehydrating beryllium hydroxide, or igniting metallic beryllium:
BeCO3 --> BeO + CO2
Be(OH)2 --> BeO + H2O
2Be + O2 --> BeO
It is used in rocket engines and transparent protective over-coating on aluminised telescope mirrors. It is also used in high-performance semiconductor parts and other electrical components because it has good thermal conductivity while also being a good electrical insulator. Beryllium oxide can also be used as a structural ceramic for high-performance microwave devices, vacuum tubes, magnetrons, and gas lasers.