Miley Cyrus' engagement ring cost an estimated $250,000, according to a new report.

The actress/singer announced on Wednesday her boyfriend Liam Hemsworth had proposed on May 31 after a three-year romance.

She was later snapped out and about in Beverly Hills, California sporting a diamond-and-gold ring on the third finger of her left hand, and an expert values the jewellery at a quarter of a million dollars.

Kenneth Lejman, a senior appraiser at the Gemological Appraisal Laboratory in the Big Apple, tells the New York Daily News, "Assuming it's reasonably high quality, I would estimate it at $250,000."

Jeweler Neil Lane, who designed the 3.5-carat piece for Australian actor Hemsworth, adds, "He wanted something really romantic and beautiful... It's all handmade with a 19th century cushion-cut diamond."

Cyrus and Hemsworth began dating after they met on the set of "The Last Song" in 2009.