An insulating glass-ceramic substrate for synthesizing graphene includes discrete, crystalline, nanophase metallic regions capable of catalyzing graphene growth. The nanophase regions may be formed by thermal treatment of a glass-ceramic substrate containing the corresponding metal oxide. Single layer and double layer graphene are prepared on the modified glass-ceramic substrate in a vacuum chemical vapor deposition (CVD) process from hydrocarbon precursors. The graphene-coated glass-ceramic substrate is electrically conductive.