The melting point of sapphire window is approximately 2040 degrees Celsius or 3704 degrees Fahrenheit. Sapphire is a crystalline form of aluminum oxide (Al2O3), and it has a very high melting point due to the strong ionic bonds between its aluminum and oxygen atoms.
Sapphire windows are commonly used in high-temperature and high-pressure applications such as gas and oil sensors, aerospace components, and scientific instruments.