Magnetic Building Block

FIG. 1 is a top perspective view of a magnetic building block showing my new design; FIG. 2 is a bottom perspective view thereof; FIG. 3 is a top view thereof; FIG. 4 is a bottom view thereof; FIG. 5 is a left view thereof; FIG. 6 is a right view thereof; FIG. 7 is a front view thereof; and, FIG. 8 is a rear view thereof. The evenly broken lines illustrate portions of the magnetic building block that form no part of the claimed design.