Maybe they redesigned it? We don't know anything for sure. But there are several pieces of turquoises. Astrid's main necklace, is made of the turquoise drops/tops of the diamond tiara and it has several pendants to make the necklace longer or shorter, or to have pendants. There are also a similar necklace that was one of Queen Maud's wedding gifts back in 1896, which has almost similar design as the necklace Astrid wears, but with bows between each turquoise drop.