The circle of an Ionic or Celtic cross symbolizes eternal life in Christ.
The designs repeated on each arm of this cross are tongues of fire, a representation of the Holy Spirit. The shape formed by each pair of flames suggests the ichthus, a sign of Christ's followers.
The host in center represents our Bread of Life, Jesus Christ.
The drop is a symbol for several things; Christ's blood shed for our redemption, water of baptism, anointing with oil an action which signifies the gift of the Holy Spirit in such rites as Healing, Baptism, Confirmation, and Ordination.