NOVELTY - Providing a first and a second starting material for carbothermic reduction process, involves: a) preparing quartz product containing less than or equal to 0.5 ppm (wt./wt.) boron and less than or equal to 1 ppm (wt./wt.) phosphorus from natural quartz; b) providing part of quartz product as first starting material; c) reacting part of quartz product with carbon material such as carbon black containing less than or equal to 0.5 ppm (wt./wt.) boron and less than or equal to 1.0 ppm (wt./wt.) phosphorus to produce silicon carbide product containing less than or equal to 1.5 ppm (wt./wt.) boron and less than or equal to 3.0 ppm (wt./wt.) phosphorus; and d) providing product as the second starting material.    USE - For providing a first and a second starting material for a carbothermic reduction process; and in the production of composition of quartz product and the silicon carbide product (claimed) used in solar cell panels.    ADVANTAGE - The method provides cost-effective and environmentally friendly (i.e. energy-efficient) method for production of silicon feedstock used in solar cell industry. The method provides silicon product of improved purity. The method based on carbothermic reduction of quartz followed by refining in the liquid state provides a promising alternative for the production of solar grade silicon. The method efficiently uses starting materials of higher purity. Thus, a silicon product having the characteristics demanded by the solar cell producers is obtained by a few relatively uncomplicated and energy-efficient refining steps in the liquid state following the carbothermic reduction. The starting materials are used in small particle sizes in order to reach the required purity and avoid losses when charged to reduction furnace.    DETAILED DESCRIPTION - A method of providing a first and a second starting material for a carbothermic reduction process, involves: a) preparing a quartz product containing less than or equal to 0.5 ppm (wt./wt.) boron and less than or equal to 1 ppm (wt./wt.) phosphorus from natural quartz; b) providing part of the quartz product as the first starting material; c) reacting part of the quartz product with a carbon material, such as carbon black, containing less than or equal to 0.5 ppm (wt./wt.) boron and less than or equal to 1.0 ppm (wt./wt.) phosphorus to produce a silicon carbide product containing less than or equal to 1.5 ppm (wt./wt.) boron and less than or equal to 3.0 ppm (wt./wt.) phosphorus; and d) providing the silicon carbide product as the second starting material. An INDEPENDENT CLAIM is included for a composition comprising the quartz product and the silicon carbide product formed by the method, where the composition is agglomerated, such as pelletized.