TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The step (a) comprises producing a precipitation template of an acidifying agent and water with a pH of less than 2, preferably less than 0.5, providing a silicate solution having a viscosity of 0.1-10000 poise, combining the addition of silicate solution with the acidifying agent and the addition of addition of the silicate solution with precipitation template such that pH of obtained precipitate suspension is maintained at a value of less than 2, preferably less than 0.5, optionally removing silicon dioxide, washing the resultant silicon dioxide, and optionally drying the resultant silicon dioxide. The step (b) is performed using high purity silicon dioxide with aluminum content of less than or equal to 5 parts per million (ppm), boron content of 10-0.0001 ppm, calcium content of less than or equal to 2 ppm, iron content of less than or equal to 20 ppm, nickel content of less than or equal to 10 ppm, phosphorus content of 10-0.0001 ppm, titanium content of less than or equal to 2 ppm and zinc content of less than or equal to 3 ppm. The method comprises subjecting the high purity silicon dioxide to a carbothermal nitridation in the presence of nitrogen, and reacting the high purity silicon dioxide with a carbon-containing material and ammonia. In the step (b), the high-purity carbon source is used as an organic compound of natural origin, preferably carbohydrate, graphite, coke, coal, carbon black or thermal black. The high purity carbon source is produced by pyrolysis of a carbohydrate or a carbohydrate mixture, preferably a crystalline sugar. The technical pyrolysis is carried out with the addition of silicon oxide, preferably high-purity silicon oxide. Preferred Components: The silicate solution is used as an aqueous sodium silicate solution and a mineral acid as the acidifying agent, preferably sulfuric acid. The high-purity silicon oxide has an average particle size (d50) of less than 70 mu m, preferably less than 20 mu m. EXAMPLE - No suitable example given.