Silicon carbide, also known as carborundum or SiC, is a chemical compound made from silica sand and carbon, produced through a carbothermal reduction of silica into an ultra-hard, covalently bonded material. It is an extremely rare material in nature (though abundant in space), found only as the mineral moissanite. Since 1893, silicon carbide has been produced in powder form for use as an abrasive in grinding wheels and cutting tools. Over time, it has found numerous applications, including in car brakes and clutches, bulletproof vests, LEDs, semiconductors, astronomical telescope mirrors, thermistors, varistors, electric furnace heating elements, and in the production of graphene or diamond simulants.