Devil's Heart by Lynn Raye Harris

Francesca D’Oro was just eighteen when darkly sexy Marcos Navarre swept her up the aisle — then fled before the ink on the marriage license had dried. Marcos might have given Francesca a jewel for her finger, but he stole another: the Devil’s Heart, a dazzling yellow diamond he believed belonged to his family…

Years later, Francesca, no longer so youthfully naive, is determined to reclaim the precious gem! But she’s forgotten that Marcos lives up to the treasure’s name — and dealing with the devil is always dangerous!