It just happens that my family lived less than 1 mile from the brick factory that made this brick. This brick is one of several found up in the attic of the old house in Mexico MO.  Perhaps they were leftovers from the outdoor fireplace / BBQ pit that stands in the backyard. 

Whatever the case this brick is unused.

Measurements:

Width- 4 1/2"        Length- 9"        Thick- 2 1/2"         Weight- 7lbs. 11.7oz