In a small saucepan over medium heat combine the sugar with 1/2 cup water and add in the 2 sprigs of mint leaves. Bring to a boil, stirring to dissolve the sugar. Remove from the heat and let cool.
In a large pitcher stir together the tea with the sugar syrup. Serve chilled over ice with a sprig of mint and a piece of rock candy for garnish. Add vodka, if desired.