They look like diamond earrings in a distinct 1950s style.
At the celebration of King Harald of Norway's 80th birthday.
At the Belgian state visit to India, November 2017.
Belgian state visit to Canada, March 2018.
Belgian state visit to Portugal, October 2018
Aren't these the same? http://m.zimbio.com/photos/Princess+Mathilde/Prince+Philippe+Princess+Mathilde+Belgium/5rgRdDZZp7LBeantwoordenVerwijderen
I don't think so. If you put the pictures together, the material and shape looks different.BeantwoordenVerwijderen