Coloured pictures of the aquamarine tiara:
And as a necklace:
Credit above to Ursula and her wonderful site.
The aquamarine tiara has a huge mystery to it. It's attributed to the Tsarina but it doesn't appear on the famous table photograph of the jewels definitely not as a diadem or it would seem a necklace.
When the Imperial family made their way from St Petersburg to the infamous Ekateringburg they stayed for a period in Tobolosk and I believe because of the journey periods made stops of days along the way to each. Where the Tsarina would go to local convents to pray or received visits from local nuns.
In Tobolsk jewels were given to the Mother Superior of a local convent. I pretty sure she left with them secreted about her person. This link says it was valet. Given the vastness of the collection I'd say both. This cache was discovered in 1933. The tiara is not listed or shown.
I remember a story of a diadem being found in jam jar years after the families death, I'm pretty sure in a convent, so it could be more of a one off insurance piece as it's not listed or shown above.
I would suspect that the Empress may have left insurance cache's along the route. Some or all being discovered as various convents were dissolved by the communists.
The tiara is listed as sold in 1926 but that could be an error and I don't think there's auction photograph's so it could be another piece or I'm completely mistaken. Does anyone have the catalogue or a more comprehensive list.
Again it's not on the table photograph it would seem from which most of the auction pieces were derived.
A few years ago, I can't find a link, it was listed for private sale by either Sotheby's or Christies. This means rather than by auction it's directly between seller and buyer not open for public bidding. However I'm very sure it didn't have any attribution to it. Auction you would have attracted a huge amount of publicity and you'd think a much higher price. Again unless I'm half remembering it was a private sale and not an auction.
Someone wanted a very discrete sale.
It's a piece that seems to have come out of nowhere albeit it decades ago.