In a medium saucepan over medium heat, combine fresh raspberries, chopped peaches, sugar, and filtered water. Stir gently until sugar dissolves for about 3-5 minutes.

Remove from heat and strain the syrup through a fine mesh strainer, pressing the fruit to extract as much liquid as possible. Allow the syrup to cool.

Brew black or herbal tea in a heat-proof container using about four tea bags for 5-7 minutes, then cool to room temperature.

In a tall glass filled with ice, combine equal parts peach raspberry syrup and chilled tea. Stir gently to blend.

Serve immediately, garnished with fresh fruit slices, or store syrup separately in an airtight container in the fridge for up to two weeks.