This tiara belongs to the Royal Family of the Sultanate of Brunei. It was originally made for Queen Saleha in the 1980's, and is often worn by the younger members of the Brunei royal family for weddings and special occasions.
The tiara is quite tall and substantial and works best with a high up-do. There are hundreds of diamonds in this piece, with a fine pear shaped diamond in the centre. The crescents are obviously an Islamic symbol and this is an example of Islamic jewelry art.