Nice to see this interesting necklace again. Great to see Queen Maxima digging up the royal jewel vaults!
The sautoir seems to be made of turquoises, but also of pearls and diamond stars, mounted on a gold frame. The heart-shaped pendant has more diamonds in its design (though on a golden frame too), so I wonder if these jewels could have a different origin.
A few large pictures to enjoy this beautiful surprise:
(picture credit: PPE/Nieboer/News Pictures, via ParisMatch.com)