The answer
The words “pectoral” and “encolpion” are both used to mean “on the chest.” The custom of wearing a pendant cross on the chest, suspended by a cord or chain around the neck started around the fourth century, and was frequently worn not just by members of clergy but also devout laymen. In 350 A. D., St. Macrina, St. Gregory of Nyssa’s sister, used to wear a small cross to protect her. St. John Chrysostom mentioned this custom of wearing a pectoral cross, since it was very prevalent among Christians. Now, however, Orthodox bishops and priests wear a pectoral cross on the chest or a medal that has the icon of Christ and St. Mary, especially after the council of Ephesus.
Fr. Tadros Yacoub Malaty