Lady Gaga casually wore one of the world's most famous (and expensive!) necklaces to the Oscars

It was her unusually low-key black gown that initially grabbed our attention as Lady Gaga arrived on the 2019 Oscars red carpet, but once we looked a little closer the enormous diamond around her neck distracted us entirely.

A blindingly bling-y yellow diamond set amongst several smaller (it's all relative...) diamonds, we knew we recognised the centre stone from somewhere. What took us a little longer to realise, however, was exactly where we'd seen it before.

Why the memory lapse? It may be one of the world's most famous diamonds, but this outing marks just the third time it has ever been worn in public.

Albeit in a different setting, the yellow stone was first worn by Mary Sheldon Whitehouse at the 1957 Tiffany Ball in Newport, Rhode Island, Audrey Hepburn was then granted permission to wear the diamond for publicity photographs for her iconic role in Breakfast at Tiffany's.