A bishop, from the Greek work “episkopos” (which means “overseer”), is a direct successor to the apostles. Bishops have, by divine institution, taken the place of the apostles as pastors of the church.
In ancient times, a chair was a sign of authority to teach. The bishop’s chair is called a cathedra, from the Latin word for chair and it is the presence of the bishop’s cathedra in a church that makes it a cathedral. The bishop’s chair is a symbol of the bishop’s teaching office and pastoral power in his diocese. It is also a sign of the unity of believers in the faith that the bishop proclaims as shepherd of the Lord’s flock.
The miter is the proper liturgical headdress for all bishops of the Latin Rite, including the pope. The word comes from the Greek word, “mitra,” meaning “turban.” It consists of two stiffened flaps of material joined by a headband with two fringed strips hanging from the back base of the miter. The miter as we know it today developed from the conical head covering worn by the pope that appeared in the 10th century. At first, it was used only by the pope.
The pectoral cross gets its name because it is worn over the breast, or pectus, hanging from a green cord intertwined with gold threads. There are rules determining whether it is worn over or under what the bishop is wearing. If he’s in a suit and collar, the pectoral cross is usually placed in the vest pocket with the chain showing.
The crosier is a pastoral staff that is conferred on the bishops (and abbots) at their installation. In the West, the top of the staff is curved to remind the bishop of the shepherd crook and of his pastoral care of the people entrusted to him. It is a sign of the bishop’s need to keep watch over his whole flock, sustaining the weak and faltering, confirming the wavering faith, and leading back the erring ones into the true fold.
The bishop’s ring is a symbol of the bishop’s fidelity to and nuptial bond with the Church, his spouse. It signifies the bishop’s symbolic marriage to the Church of Christ. The bishop’s ring is usually made of gold with an amethyst. The bishop’s ring was first mentioned as an official part of the bishop’s insignia in the early seventh century.
The zucchetto is a skullcap worn, particularly by prelates, since the 13th century. The pope wears a white zucchetto, cardinals wear a red zucchetto and bishops wear a purple (magenta) zucchetto. Everyone else wears black.
Sources: Catechism of the Catholic Church, Our Sunday Visitor’s Catholic Encyclopedia, The Harper Collins Encyclopedia of Catholicism.