Unfortunately, I have never been able to find a description of Princess Marie Louise's jewels for that occasion.
The shape of the tiara she wore recalled sketches of a tiara worn by her mother, Princess Helena, Princess Christian, which were in the media following a gala opera event for the State Visit of King Alfonso to the UK in June 1905.
Detail from the Sphere 17 June 1905
Illustrated London News 17 June 1905.
And from the 1911 Coronation
And a photo showing Princess Helena after the wedding of Queen Mary in 1893.
Unfortunately the photos are blurry and the sketches may not be accurate. Nevertheless I was struck by the similarity in shape.
Even more unfortunately I have never been able to find anything other than a reference to diamonds worn by Princess Christian on any of these occasions.
Description of dress and jewels 1905
Initially I thought that this might have been a second turquoise tiara belonging to Princess Helena, which may have come from Queen Victoria.
Then I realised that I had a photo of Mary Soames, WInston Churcxhill's daughter from December 1953 wearing a remarkably similar tiara to the one worn by Princess Marie Louise.
The occasion was from the Nobel ceremony in December 1953 when Churchill was awarded the Nobel prize for Literature.
Once again the press didn't have any information about the jewels worn, only that Lady Churchill and Mary Soames wore diamonds.
When I placed the tiara worn by Marie Louise against that worn by Mary Soames, I began to wonder if they were actually the same tiara, despite the different surmounts. Perhaps they aren't. What do others think?
That still leaves the mystery of the tiara worn by Princess Marie Louise. Could it be the one worn by her mother? If so what were the darker coloured gemstones? If not, where did this tiara come from?