Ohhh thank you so much!
I’m no expert but the shape & design looks a bit the same.
Although the pictures are not very clear…. It seems that the diamond circle-design are the same in both tiaras.

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That is Princess Alexandra of Ysenburg and Büdingen, Princess Welf Henry of Hanover , the sister-in-law of Queen Frederica, who wore this Diamond Tiara for King Paul of Greece’s 60th Birthday Banquet and also the Wedding Ball of Prince Juan Carlos of Spain and her niece, Princess Sophia of Greece, at the Royal Palace of Athens .
