A glass-ceramic composition contains first ceramic particles principally containing forsterite; second ceramic particles principally containing at least one selected from the group consisting of calcium titanate, strontium titanate, and titanium oxide; and borosilicate glass particles containing about 3% to 15% lithium oxide, about 20% to 50% magnesium oxide, about 15% to 30% boron oxide, about 10% to 45% silicon oxide, about 6% to 20% zinc oxide, 0% to about 15% aluminum oxide, and at least one additive selected from the group consisting of calcium oxide, barium oxide, and strontium oxide on a weight basis. The content of the borosilicate glass particles is about 3% or more; the lower limit of the content of the additive is about 2%; and the upper limit of the additive content is about 15%, about 25%, or about 25% when the additive is calcium oxide, barium oxide, or strontium oxide, respectively, on a weight basis.