Kim Kardashian buys Attallah Cross necklace worn by Princess Diana

Kim Kardashian has bought a bold cross necklace once favored by Princess Diana -- and which has not been seen in public since the late royal's death in 1997, according to Sotheby's, the global auction house that coordinated the significant purchase.

The Attallah Cross, an amethyst and diamond pendant, was made in the 1920s. In the 1980s, it was owned by Naim Attallah, a former group chief executive of the luxury jewelry company Asprey and Garrard. Sotheby's said its diamonds are about 5.25 carats, and overall, the statement piece measures approximately 5.3 inches by 3.7 inches.

Princess Diana notably wore the Attallah Cross on Oct. 27, 1987 at a charity gala held in support of Birthright, a charity supporting pregnancy and childbirth research. Now known as Wellbeing of Women, the charity has expanded its scope since the 1980s to encompass research focused on women's health.

Diana is said to have greatly favored the Attallah Cross, which features a flowery design -- known as fleurée style -- square-cut amethysts and circular-cut diamonds. She wore it on numerous occasions, but after her unexpected death on Aug, 30, 1997, the Attallah Cross was never worn or brought out in public.

Kardashian reportedly acquired the Attallah Cross for $197,453, over double its pre-auction estimate, and beat three other bidders for the bejeweled piece.