Mosaic Plaque with Unity Knot. Opaque brick red and multicolored glass; surface slightly dull through weathering and slight pitting; molded with inlaid decoration; pure black rectangular plaque or block showing a tower-like motif (lighthouse of Alexandria (?); it is less likely that it shows a phallus); the complete scene includes a tower like upright in black and yellow hatching standing on a similar base and being surmounted by an onion shaped white top; two wings of the butterfly type attached to the center; the colors being white, blue and red.