Catechism of the Catholic Church §1640 — excerpt
Thus the marriage bond has been established by God himself in such a way that a marriage concluded and consummated between baptized persons can never be dissolved.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: CIC, can. 1141