Boron carbide (chemical formula: B₄C), commonly referred to as black diamond, is an inorganic compound typically appearing as a gray-black microcrystalline powder. Renowned for its exceptional hardness, it ranks as the third hardest known material, surpassed only by diamond and cubic boron nitride. With a Mohs hardness of approximately 9.5, this lustrous black crystalline material exhibits superior hardness to silicon carbide while maintaining lower brittleness than most ceramic materials.
