Hi, I believe this is Empress Alexandra Feodorovna's tiara, which is now in the possession of the government of the Philippines after being confiscated from Imelda Marcos. The tiara is still being kept in the Central bank. There has been talk of the government auctioning it, but so far nothing has come out yet.
This is one of the most recent photos, found on a local program which broadcast the news that Imelda Marcos' jewels were being re-appraised: