Princess Diana’s engagement ring was reportedly once dubbed as the Commoner’s Sapphire.

On the online forum site Quora, royal fans discussed how Princess Diana's engagement bling got this reputation. Vivian Leese, a former jewelry store worker, said that the name was probably derived from Princess Diana’s roots. Before she was engaged to Prince Charles, the Princess of Wales was known as a commoner.

According to Leese, Princess Diana’s 30-carat Ceylon sapphire ring shows a bit of purple rather than the usual midnight blue shade of a traditional sapphire. The ring was already in stock, which means that it wasn’t designed specifically for her.

Christalle Altunel debunked the previous fan’s explanation by saying that the term commoner’s sapphire actually came from the fact that no one among the royal family liked the engagement ring that Princess Diana picked out from a Garrard catalog.

“Despite the fact that Queen Elizabeth’s own daughter Princess Anne was given a sapphire ring by her betrothed Captain Mark Phillips, some within the palace took serious issue with Diana’s choice at the time and this was where the term Commoner’s Sapphire first originated,” she said.

Seren Verch Dafydd, a physics graduate from the Ohio State University, said that Princess Diana’s engagement ring was never referred to as the commoner’s sapphire. The term was only used after Prince William passed on the engagement ring to Kate Middleton when he asked for her hand in marriage.

“The media and jewelers began calling the ring ‘Commoner’s Sapphire’ after HRH Prince William gave it to his fiancée, Catherine Middleton, alluding to the fact that she was a commoner, not a member of the nobility. Personally, I find the name insulting,” she said.

Princess Diana and Prince Charles tied the knot on Aug. 31, 1997. However, their marriage only lasted for over a bit of a decade. The couple’s divorce was finalized in 1996 before Princess Diana’s death one year later.

RELATED STORIES