In a small dish, combine the blackberries with 1 tsp. of the flour and 1 tsp. of the sugar. Stir to coat the berries, and set aside.
In a mixing bowl, stir together the remaining flour, sugar, with the salt, baking powder and lemon zest. Add the butter cubes and work the butter into the dry ingredients until it is in pea-size pieces and distributed throughout the flour.
Stir the lemon juice into the blackberries. Add the berries to the dough and gently stir to incorporate.
Add the milk and stir until the dough comes together and you can form a ball.
Transfer the dough ball to an ungreased baking sheet with parchment paper. Press the ball out to form a flat, round disk about ½-inch in thickness.
Cut the disk like a pie, into 8 equal pieces. Sprinkle the sugar evenly over the scones.
Bake for 17 to 20 minutes, or until the center is firm and a toothpick inserted comes out clean. Allow the scones to cool for at least 5 minutes.
Use a serrated knife to make the final cuts through the scones following the pattern made before baking. Serve warm or at room temperature.