The "Party in the USA" singer made headlines over the weekend when she stepped out at Muhammad Ali's Celebrity Fight Night XIII event in Phoenix, Arizona wearing a giant sparkler on her engagement finger. Despite its size, a source told Us Weekly that Hemsworth, 22, has not popped the question.
Still, Cyrus' new bauble is something to behold. "Miley's ring has all the elements of an engagement ring, with an impressive round diamond of approximately 3 carats set in a floral design," says jewelry expert Michael O'Connor, who estimates the ring cost $50,000.
"We can only assume the real engagement ring would be set in platinum with an even larger diamond," O'Connor tells Us. "Fortunately for Liam, a platinum setting like this starts at about $1,000, so he will be able to put more money into an even larger diamond."
Cyrus began dating Hemsworth, her Last Song costar, in 2009. "I try to be romantic," The Hunger Games' Hemsworth once told Us of his on-and-off love. "I surprise her with some flowers or a gift, or take her out to dinner."