A stone placed in a prominent corner of the foundation of a church, or other building, laid at a ceremony which marks the beginning of the erection of the superstructure. It is inscribed with the date, and has a cavity to receive coins and other mementoes of the time and circumstances. The corner-stone of an ecclesiastical building symbolizes Christ, who is the Corner-stone of faith and Foundation of the Church. It also symbolizes Saint Peter, the first vicar of Christ, to whom Christ said: "Thou art Peter [Greek: petra, rock]; and upon this rock I will build my Church" (Matthew 16).