Many people ask about the elaborate cross seen on the album cover and in the background of this page.  It's called the  Cross-Rho Celtic.  This compound cross of my own design combines the chi-rho with a Celtic cross and Latin cross.  Here's  a look at  each element. 
The Chi -Rho,  XP, is one of the most popular Christian symbols of antiquity. Still seen in the worship and liturgy of many Christian churches, the CHI RHO was formed of a combination of the two Greek letters chi X and rho P. They form a monogram for Jesus Christ's name, Christos. The X makes the "k" sound and the P makes an "r" sound in the Greek alphabet (Myron). It was also inscribed on large stones all over Ireland and Scotland by Celtic Christians.

"The Irish Catholic priest will have no hesitation telling you that the circle of the Celtic Cross is a symbol of eternity that emphasizes the endlessness of God’s love as shown through Christ’s sacrifice on the cross. That is unless he says the circle is a halo. He may go on to explain that the crucifixion is important not just as an event at a certain point in time but, as the circle symbolizes, as the unending mystery of how through the crucifixion and resurrection Christ continues to offer the hope of salvation to the faithful throughout all time."  (Walker)

"There is a legend of how St. Patrick when preaching to some soon to be converted heathens was shown a sacred standing stone that was marked with a circle that was symbolic of the moon goddess. Patrick made the mark of a Latin cross through the circle and blessed the stone making the first Celtic Cross. This legend implies that the Saint was willing to make ideas and practices that were formerly Druid into Christian ideas and practices. This is consistent with the belief that he converted and ordained many Druids to lives as Christian priests." (Walker)