Attorneys for the Pirates of the Caribbean star quizzed Ms Heard about the love notes, in which she described her “gorgeous honeymoon” during the proceedings on Tuesday.
The courtroom was read entries from a journal that Ms Heard said the couple kept to share love notes.
“True love isn’t about just the madness of passion or instead picking the safety of peace. No, it’s about both.
“I still, perhaps more than ever, want to rip you apart, devour you and savor the taste,” she wrote in May 2015, two months after an alleged incident took place in which Mr Depp claimed she threw a bottle of vodka at him, severing the top of his right middle finger.
Ms Heard denies causing the finger injury.
In another excerpt after their July 2015 honeymoon aboard the Orient Express train, Heard said she “couldn’t imagine a more gorgeous honeymoon,” and added, “I love you more and more every passing day.”
Ms Heard had told jurors on Monday that she had been assualted by her husband and had a T-shirt wrapped after her neck during the trip.
A month later, she wrote that Depp was “my cornerstone, my heart, my all.”
“You are my life. I hate it when we fight. I hate having hurt you. I love you more than anything,” she wrote.
Asked about entries, Ms Heard said she tried to “nurture as much peace as she possibly could,” and that “when things were good they were really good.”
His lawyers also asked her about a knife which she bought as a gift for Mr Depp.
“This is the knife you gave to the man who would get drunk and violent toward you?” lawyer Camille Vasquez asked.
“This is the knife I gave him as a present, yes,” she said, adding that she did not think he would stab her with it.
The couple married in February 2015 and their divorce was finalised around two years later.
Mr Depp, 58, is suing his ex-wife for $50 million, saying she defamed him in a op-ed published in the Washington Post when she claimed she was a victim of domestic abuse.
The article never mentioned Mr Depp by name, but his lawyer told jurors it was clear that Ms Heard was referencing him.
Mr Depp, once among Hollywood’s biggest stars, said his former wife’s allegations have cost him “everything” after he was replaced in the Fantastic Beasts film and a new Pirates of the Caribbean movie was put on hold.
Ms Heard’s attorneys have argued that she told the truth and that her opinion was protected free speech under the US Constitution’s First Amendment.
The 36-year-old actress is countersuing Mr Depp for $100 million, arguing that Depp smeared her by calling her a liar.
Mr Depp has denied all allegations against him.
The trial, at Fairfax County Courthouse in Virginia, continues with closing arguments scheduled for May 27.