heart of stone

plural hearts of stone

1. figurativelyA hardhearted character, stern or cruel nature.

   She's got a heart of stone.

   2 more examples

   You've got a heart of glass or a heart of stone / Just you wait 'til I get you home

   1986, “West End Girls”, in Please, performed by Pet Shop Boys

   It would take a heart of stone, or an opposition supporter, not to feel some measure of sympathy for a player whose career has come to a standstill at club level and does not seem able to catch a break when he does make a rare appearance.

   2023 September 12, Phil McNulty, “Scotland 1-3 England: 'Complete package' Jude Bellingham puts concluding flourish on world-class performance”, in BBC Sport

   Antonyms: heart of gold