I suspect that the emeralds are now in private collections. Some have been traced -- in particular by Vincent Meylan in his book Christie's. The jewellery archives revealed.

As Vincent Melyan notes (pp. 249-53), after Queen Isabella lost her throne (1868) and fled to Paris, many of her jewels were sold in Paris in 1878.

Some reappeared at later Christie's auctions. Three of her emeralds were in the collection of Baron Gustave de Rothschild and were auctioned in Geneva in 1992. These were 2 square emeralds set in diamond borders and a rectangular emerald, also in a diamond border, set as the centre piece/clasp of a pearl bracelet.

It would be interesting to know where the very large emerald which was the centre piece of the Queen's stomacher went.