碳化硅（Silicon carbide，化学式SiC）俗称金刚砂，宝石名称钻髓，为硅与碳相键结而成的陶瓷状化合物，碳化硅在大自然以莫桑石这种稀罕的矿物的形式存在。自1893年起碳化硅粉末被大量用作磨料。将碳化硅粉末烧结可得到坚硬的陶瓷状碳化硅颗粒，并可将之用于诸如汽车刹车片、离合器和防弹背心等需要高耐用度的材料中，在诸如发光二极管、早期的无线电探测器之类的电子器件制造中也有使用。如今碳化硅被广泛用于制造高温、高压半导体。通过Lely法能生长出大块的碳化硅单晶。人造莫桑石的宝石就是通过切割由Lely法制备的大块碳化硅单晶来获得的。

Silicon carbide (SiC), also known as carborundum /kɑːrbəˈrʌndəm/, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been mass-produced 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. 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. Large single crystals of silicon carbide can be grown by the Lely method; they can be cut into gems known as synthetic moissanite. Silicon carbide with high surface area can be produced from SiO₂ contained in plant material.