The stunning pink sapphire is surrounded by diamonds, and is strikingly similar in style to the ruby engagement ring her father, Prince Andrew, gave to Sarah 'Fergie' Ferguson when he proposed in 1986.
The 27-year-old royal's new sparkler is estimated to be worth £100,000 ($A175,112), UK television program, Posh Pawn reports.
Gemologist Deborah Papas told The Sun, 'It is a padparadscha sapphire surrounded by 10 brilliant cut diamonds and two pear cut diamonds to give an edge to the standard classic cluster.
'Padparadscha is the name given to the corundum gem that bears a mixture of red and yellow, a sort of cross between a ruby and yellow sapphire. This beautiful gem is considered amongst the rarest and most valuable of all the corundum varieties.'
Meghan Markle's engagement ring is estimated to be worth £50,000 ($A87,556), almost half the value of Harry's cousin.
Prince Harry designed Meghan's ring himself and was created by court jewelers Cleave and Company using a diamond sourced from Botswana, where the couple spent much of their time while their relationship was still under wraps. The ring also features two smaller stone's from the late Princess Diana's personal collection.
The princess and her 31-year-old partner have been dating for six years, and will tie the knot between September to December of this year.