FIG. 1 is a top, front, and right side perspective view of a heart-shaped stone;
FIG. 2 is a bottom, rear, and left side perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a right side view thereof, the left side view being a mirror image thereof;
FIG. 6 is a front side view thereof;
FIG. 7 is a rear side view thereof;
FIG. 8 is a top, front, and right side perspective view of an alternative embodiment of a heart-shaped stone;
FIG. 9 is a bottom, rear, and left side perspective view thereof;
FIG. 10 is a top view thereof;
FIG. 11 is a bottom view thereof;
FIG. 12 is a right side view thereof, the left side view being a mirror image thereof;
FIG. 13 is a front side view thereof; and,
FIG. 14 is a rear side view thereof.
The broken lines in FIGS. 1, 2, 4, 5, 6, 7, 8, 9, 11, 12, 13, and 14 depict portions of the heart-shaped stone that form no part of the claimed design.