Ingredients
2 cups blackberries
1/2 cup lime juice
3/4 cups white tequila
2 cups ice cubes
1/4 cup sugar

Method - The Procedure
Puree blackberries in a blender. Force puree through a fine sieve into a small bowl and discard solids. In a cocktail shaker, combine 1/2 cup puree and remaining ingredients and shake well.