Silicon carbide (SiC), also known as carborundum (/ˌkɑːrbəˈrʌndəm/), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite.

Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both.

Silicon carbide is widely used in different industries:

• Abrasive and cutting tools
• Structural material
• Automobile parts
• Electric systems
• Electronic circuit elements
• Astronomy
• Thin filament pyrometry
• Heating elements
• Heat shielding
• Nuclear fuel particles and cladding
• Jewelry
• Steel production
• Catalyst support
• Carborundum printmaking
• Graphene production
• Quantum physics
• Fishing rod guides