Legendary Blue Diamond Three — mark Stewart

Legendary blue diamond three is the third novel in the trilogy.
Zac and Peyton are in love. The minute they discover both their ancestors were enemies the foundation of their relationship is ruptured. After reading the long lost telegram, Zac's attitude instantly changes. He believes the blue diamond ring belongs to his family and orders Peyton to hand it over. For the first time Peyton actually feels afraid of him.
Now the truth behind the blue diamond ring is unguarded Peyton is torn between her boyfriend and family commitments to protect the secret of blue diamond ring.
When Peyton and Audrey refuse to give him the ring Zac decides to take matters into his own hands by threatening to murder Peyton. The ring is hesitantly surrendered. Zac further exposes the secret of the legendary blue diamond when he tries to sell the item. Now Peyton and her mother have to steal it back before anyone else knows of its existence. Peyton's gran calls upon an old friend for help. If she plays her cards right he'll agree, if not the secret will finally be uncovered.