The Swedish Aquamarine Tiara

This tiara is in the "Kokoshnik" style - it's the Russian word for "cockscomb", and this style of tiara originated in Russia.

Here is Princess Madeleine of Sweden wearing the Swedish Aquamarine Kokoshnik Tiara:

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This tiara came into the hands of the Swedish royal family though Margaret Connaught, who became the bride of King Gustaf VI Adolf of Sweden.

It is made of giant aquaramines interspersed with small diamonds. No-one knows how the Connaught family obtained the tiara, but some believe it was made by the German jeweller Koch.

Of the Swedish princesses, Princess Madeleine wears it most often as the aquamarines match her blue eyes.