Might be similar rings. Looks like a ring from the Boucheron Bridal Collection.
There is a Japanese Boucheron website as well, and it costs ¥143,850 (US$1466). In its description - 明るい輝きで永遠の愛を祝福するリングです。 Akarui kagayaki de eien no ai o shukufuku suru ringu desu. A ring that celebrates eternal love with its radiance.
Maybe Shukan Josei had this in mind when they allegedly had the scoop of a super popular idol getting married.
By the way, the first episode of Hana Yori Dango aired 8 years ago today, 21st October 2005 ( •ᴗ•)