Here we have a love it or hate it piece that may be worn rather infrequently these days, but packs quite a history nonetheless.
In The Queen's Jewels, Leslie Field says that this was commissioned in 1830 using diamonds that had belonged to George III. She goes on further to state that Queen Victoria left the piece to the Crown, Queen Mary inherited it in 1910, and that Mary gave it to Queen Elizabeth (the future Queen Mother) in 1937.
The Royal Collection tells a different story, and since they are the authorities, I'm buying their version of the tale. They state that Queen Mary had the piece made in 1919 from a necklace she received from Queen Victoria as a wedding present. (You can magnify the piece at the Royal Collection site, which greatly improves your drooling material.) They also dispel the Hanoverian myth by specifying that Victoria bought the necklace from Collingwood & Co. jewelers in 1893. I'll wager a guess that the converted necklace in question is the one we see here:
the bridal veil. (Does it appear to not be centered properly to anyone else? This has always bugged me about the Queen's wedding pictures.)
I wonder, though, if we might see it on Zara now instead. I'd rather see Zara in the Meander Tiara from her mother on her wedding day, but perhaps the sentiment of wearing the tiara worn by her grandmother and her mother will win the day?
Photos: PA/Munn/Fields/Royal Collection