I just finished rereading Hannah Pakula's biography of Queen Marie of Romania.
In a chapter it was mentioned that she wore her best tiara to attend a performance
put on by a friend of hers. So what could that tiara be?

The diamond and pearl tiara made by Cartier eventually seemed to have went to
Elisabetha, since she was seen wearing it to her parent's coronation and in one or
two photos. The sapphire tiara later went to Ileana.

Which leads to my second question, which will be started in another topic...

Wow, thanks for the links Ursula! The closeup of Queen Helene was amazing - what was the provenance of her tiara and what happened to it??? Will post it on the old board.