Chi Rho Cross Hanging Christmas Tree Ornament. From Romans Inc, 2001. The Cross is the most prominent of all Christian Symbols. The Chi Rho Cross was used by Emperor Constantine, which led to the introduction of Christianity as the state religion of the Roman Empire. The Cross is Metal with Green Sparklies. Cross is About 4 1/4 Inches at Tallest and About 2 Inches at Widest. In Original Box with all Twist Ties still attached.