Lady Rosebery Pearl Tiara. On the web I found This striking tiara was once the property of a woman said to have been the wealthiest woman in England, Hannah, Countess of Rosebery (1851-1890), and was an important member of a jewel collection rich enough to rival a royal collection. The Rosebery Pearl and Diamond Tiara has a base of clusters of large button (bouton) natural pearls surrounded by old-cut diamonds and a top of seven natural pearl and diamond drops, all set in silver and gold. It's a versatile diadem with multiple detachable pieces; the top pieces can be removed (in the same fashion as the Londonderry Tiara, also crafted by Garrard) leaving the bottom row as a smaller tiara, and the buttons can also be used to form six brooches with the top pieces as pendants. A bracelet and brooch, each featuring more clusters of button pearls and diamonds, completed the set.