In their book, The Theology of Christian Perfection, Fr. Jordan Aumann, O.P., and Fr. Antonio Royo, O.P., close their rich and helpful discussion of how to reach Christian perfection in everyday life with a discussion of the mystical miracles in the lives of the saints.
Here are some extraordinary examples (by no means inclusive):
Knowledge of the secret of hearts was given to Sts. Thomas Aquinas, Philip Neri, Joseph of Cupertino, John of God, Rose of Lima, John Vianney.
Hierognosis (immediate recognition of any person, place or thing that is holy, blessed or consecrated as opposed to things that are not) was the gift of Catherine Emmerich and Sts. Frances of Rome and Lydwina.
St. Philip Neri’s love for God was so intense that it was often visible as flames coming from his eyes and head.
St. Francis of Assisi received the stigmata (wounds of Christ’s Passion) as did Padre Pio.
Jesus sweat blood in the Garden of Gethsemane. This was also experienced by St. Lutgard and Bl. Christina. Theresa Neumann shed tears of blood.
Some saints experienced an exchange of hearts, presumably with Christ, most notably Sts. Catherine of Siena, Margaret Mary Alacoque, Magdalen of Pazzi and Catherine Ricci. A scar was sometimes visible.
Others fasted beyond the power of natural endurance, for example, St. Catherine of Siena and Bl. Angela de Foligno.
Some saints went for long periods without sleep like St. Peter Alcantara and St. Rose of Lima.
Even a modern saint could bilocate, most recently St. Padre Pio, but this also includes Sts. Francis Xavier, Alphonsus Liguori, Martin de Porres and Ven. Mary of Agreda.
Some mystics seemed to radiate light like Moses, and Sts. Ignatius of Loyola, Francis de Sales, and Charles Borromeo.
A sweet odor often comes from the tomb, relic or body of a saint like Gemma Galgani, Dominic, Rose of Viterbo and Raymond Pennafort. Of course, miracles attributed to St. Therese of Lisieux are often accompanied by the smell of roses.
Then there are the incorruptible bodies of which I have seen my fair share like Bernadette of Lourdes, Vincent de Paul and Pope John XXIII.
Fathers Aumann and Royo pass no judgement on these occurrences saying “that no phenomenon should be attributed to a superior cause if it can be explained by an inferior one.” However, the extraordinary and miraculous examples cited above “show us that God is truly wonderful in His saints.”