Combine apricots, raisins, sultanas, rind and grated dark chocolate in a small bowl. Roll teaspoons of mixture into balls, refrigerate overnight. Break extra chocolate into pieces, place in top of a double saucepan with butter over simmering water. Stir until smooth or microwave on HIGH for 2 minutes. Dip each fruit ball in chocolate until evenly coated. Place balls on foil-covered trays; allow to set in a cool place. Store balls in airtight container in refrigerator. Makes about 25