Carey's publicist told the publication, 'Mariah has been very vocal recently about her choice to move forward in her life surrounded by positivity.
'That requires leaving emotional and material baggage behind, including an old engagement ring from an ex-boyfriend.'
An insider added, that Carey's team have been trying to keep the sale as quiet as possible.
'A confidentiality agreement was signed, but the jeweller is currently selling it, and there’s only one such ring,' they told Page Six. 'Mariah Carey’s public relations people are desperately trying to keep the story from the press, and have threatened the jeweller with litigation if he discloses her name.'
Carey and Packer began dating in June of 2015 after being introduced by film director Brett Ratner.
The billionaire proposed in January 2016, but the relationship ended in October.
Packer has since labelled the relationship 'a mistake.'
'I was at a low point in my personal life,' he said. 'Brett Ratner put Mariah and me together. She was kind, exciting and fun. Mariah is a woman of substance. She is very bright. But it was a mistake for her and a mistake for me.'