From Her Majesty's Jewel Vault: The Dorset Bow Brooch. The Dorset Bow Brooch was a present to Queen Mary for her wedding to the future George V in 1893 from the County of Dorset (unsurprisingly). It’s composed of diamonds set in gold and silver and was made by Carrington & Co.
Greville Scroll Brooch. Scroll of diamonds around 3 pearls, set in platinum. These are the jewels of Mrs. Ronald Greville, left to the Queen Mother in 1942, made by Cartier using some of her own stones in 1929. The third pearl is actually a drop pearl, but it seems to be worn with the drop on top mostly. The brooch passed to the Queen after the Queen Mother's death in 2002.
The Queen`s Floral Flowers in a Vase brooch, it features a fairly large aquamarine with a diamond base, & what looks like flowers in a vase made from sapphires, rubies & amethysts with diamond centres & stalks.
This Russian Sapphire & Diamond brooch, once belonged to the Russian Imperial family sold at Christies in Switzerland in 2011 & appears to be the counterpart to the Queen`s slightly smaller, round brooch as they have the same setting & design. They were a wedding present to Princess Marie of Hesse when she became the bride of the future Tsar Alexander II in 1841. This one could be the clasp on a pearl necklace (or fit in to a tiara) & the Queen`s, the clasp on a pearl bracelet.