Jorge what a wonderful explanation of the Dom Luís diadem and Queen Amélia wedding gifts!!
I also have no information on the provenance of these earrings. I find them beautiful, and they were the perfect match for the wedding diadem. I know nothing about the quality of the gems, but the earrings appear to be quite valuable since those diamonds are of considerable size. They seem to me as being older pieces, not a recently made pair of Diamond earrings. I never seen them worn by Dona Maria Francisca, and I have excluded Queen Amélia because she never had her ears pierced. Very, very unlikely to have come from Queen Maria Pia since her jewels were auctioned. So where did they come from?? Another mystery for us to try to solve.
Queen Amélia's two wedding gift necklaces are another mystery to me. The Diamond mirrorred necklace (a perfect copy of the diadem) was only seen in the sketches made of the wedding gifts and published in the newspapers of the time. Queen Amélia wore the diadem for several oficial photos over many years, but she never wore the matching necklace. I don't know of a single photo of her wearing that necklace. I don't have any knowledge of what happened to it.
The Diamond and saphire necklace (gift from Dom Carlos) seems to have been worn on one single photo session (the same of the beautiful pic you posted). The photo session took place shortly after the wedding and the necklace was never to be seen worn by the Queen on any other pic. I don't know what happened to it either. I find this necklace very modern in its design, it could be worn beautifully nowadays. I actually find it similar in design to the modern Cartier collection necklace that Diana de Cadaval wore on her prewedding ball. Here's a pic:
It seems the diadem (I also call it this way because its the way Queen Amélia would refer to it) is quite flexible. The Queen wore it on a more open display (your photo) in her latter years, but as a young Duchess/Queen she wore it like a small more closed coronet, as it was fashionable in those days.
Dona Isabel also wore a more closed version of the diadem on her wedding day. The beautiful pic bellow of the happy bride wearing her glittering jewelry was posted on this board sometime ago by Tamara:
The second time Dona Isabel wore the Dom Luís diadem (13 years after her wedding, on oficial photos) she wore it on a more open version (I will post the entire photo of the Duchess soon, when we discuss the other jewelry pieces she is wearing). Again, the pic bellow was posted previously here by Tamara. A most beautiful and classical jewel in my opinion.
It seems you have cleared up its ownership Jorge, because I've also read some speculation on if it was or not the property of the Foundation. I am very glad it is not!!!