No, they are not the same but I have no idea what happened to either of them.
Queen Astrid's diamond riviere from the King Gustaf V of Sweden
pic first posted by Tamara
And Princess Lilian's diamond necklace, I always just assumed that the large diamonds were from the Nine Provinces Tiara but I guess that's what I get for assuming something. Also this necklace is not the same as the bottom of the floral tiara because she is wearing both in one of the pictures.
Is this the same necklace?
Are these necklaces all made using the diamonds from the Nine Provinces Tiara?
I think Princess Lilian might be wearing the two extra diamonds as earrings.