Oscars 2019: Lady Gaga Stuns In Alexander McQueen, $30M Diamond Necklace [PHOTOS]

Lady Gaga brought her A-game to the 2019 Oscars red carpet, looking absolutely gorgeous in a black gown and a diamond necklace worth $30 million.

On Sunday, Gaga, who is nominated for best actress for her role in "A Star Is Born," donned a sculptural black gown from Alexander McQueen that featured a flared hip detail and gloves in a matching color. The singer-actress styled her platinum-colored hair in a chic updo.

What drew more attention, however, was the 128.54-carat yellow Tiffany diamond around Gaga's neck. The cushion-cut 141-year-old canary yellow jewel was previously worn by Audrey Hepburn in the promo shots for the now-classic movie, "Breakfast At Tiffany's," according to Daily Mail.

Gaga, whose real name is Stefani Joanne Angelina Germanotta, is only the third woman to have ever worn the yellow Tiffany diamond. It was first worn by Mrs. Sheldon Whitehouse at the Tiffany Ball in Newport in 1957, then Hepburn four years later for a publicity photo shoot for the jewelry company in 1961.

The legendary canary yellow diamond was discovered in the Kimberly Mines of South Africa back in 1877. Charles Lewis Tiffany, who founded the iconic jewelry company in 1837, purchased the gem, which was 287.42 carats at the time, a year after its discovery. Tiffany was the one who cut the diamond into a 128-54-carat cushion-shape jewel that is now usually displayed at the Tiffany & Co. flagship store in New York City.

The Tiffany diamond's current setting, which took over a year to be completed, was made in 2012 in honor of the company's 175th anniversary. It is currently mounted on an incredible necklace with 16 cushion-cut diamonds of over 80 carats in total and 46 round brilliant diamonds of over 15 carats in total. Gaga's earrings, made of platinum and 18K yellow gold, were also from Tiffany & Co.

This marks Gaga's first public appearance since she and Christian Carino called off their engagement earlier this week. The two started dating in 2017 and got engaged a year after.

Meanwhile, Gaga and Bradley Cooper's duet from "A Star Is Born," titled "Shallow," has won best original song at the 2019 Oscars, the Washington Post reported. The song, which was written by Gaga, Mark Ronson, Anthony Rossomando and Andrew Wyatt, marks the singer-actress' first ever Academy Award win.

During her acceptance speech, Gaga was in tears as she thanked her family and Cooper. “If you have a dream, fight for it," she said. "There’s a discipline for passion, and it’s not about how many times you get rejected or you fall down or get beaten up. It’s about how many times you stand up and are brave and keep going.”