Aluminium oxynitride Wikipedia
Aluminium oxynitride or ALON is a ceramic composed of aluminium, oxygen and is marketed under the name ALON by Surmet Corporation. ALON is optically transparent (≥80%) in the nearultraviolet, visible and midwaveinfrared regions of the electromagnetic spectrum. It is four times harder than fused silica glass, 85% as hard as sapphire, and nearly 15% harder than magnesium