Abstract: This invention relates to a novel hard material which may be used as an abrasive and a method of making the material. The material consists essentially of B.sub.x C.sub.y N.sub.z, wherein x, y and z can have any value greater than 1, in tetrahedral form. The preferred material is BCN. The material is made by subjecting an appropriate source of boron, nitrogen and carbon to conditions of temperature and pressure sufficient to produce the material. The preferred method is to subject boron carbonitride in hexagonal or amorphous form in the presence of an appropriate solvent for the substance such as an aluminium/iron alloy to a pressure exceeding 50 kilobars and simultaneously a temperature exceeding 1300.degree. C.