Abstract: A process of purifying crystalline quartz to remove impurities within the lattice structure comprising the steps of heating the quartz to the tridymite polymorphic form and evaporatively reacting the heated quartz with an aqueous acid solution reactive with the impurities in the quartz to form water soluble metal salts. The residue of the evaporative reaction is washed with water to dissolve the metal salts leaving purified crystalline quartz. The disclosure also includes the product of the process.