The ornamental design for a necklace, as shown and described.
FIG. 1 is a front view of the necklace of the present design in the closed position;
FIG. 2 is a front view of the necklace shown in FIG. 1 in the open position;
FIG. 3 is a back view of the necklace shown in FIG. 1 in the closed position;
FIG. 4 is a back view of the necklace of FIG. 1 in the open position;
FIG. 5 is a front perspective view of the necklace of FIG. 1 in the closed position;
FIG. 6 is a front perspective view of the necklace of FIG. 1 in the open position;
FIG. 7 is a perspective view of the necklace of FIG. 1 in the closed position;
FIG. 8 is a perspective view of the necklace of FIG. 1 in the open position;
FIG. 9 is a side view of the necklace of FIG. 1 in the closed position;
FIG. 10 is a side view of the necklace of FIG. 1 in the open position;
FIG. 11 is a top view of the necklace of FIG. 1; and,
FIG. 12 is a bottom view of the necklace of FIG. 1.
The evenly dashed broken lines depict portions of the necklace that form no part of the claimed design. The evenly dashed broken lines that define unshaded regions and that are adjacent to claimed surfaces depict boundaries to the claim. The uneven dot-dash broken lines depict boundaries to the claim and form no part thereof.