Indeed , this was discussed since years and years and no answer. The Monpezat were not rich, Henrik was not.
From Where are coming the 2 diamonds of 6 carats, from his grand father when he was in Indochina , or stones from the Danish vault.
Never a clear explination was given.
Van Cleef and Arpels who made de golden Ring said it is the most expensive engagement ring in Europe.

[quohave seen that in print somewhere... just cannot remember where... will try to look in some books...

And I have also seen somewhere that the stone(s) (one or more?) in the ring should be old family stones from "Count" Henri's family... but cannot remember the source of that either