A wonderful find, Torkel. I found the following possible line of inheritance from Queen Charlotte based on an amethyst snuff box. An extremely long long shot I know.
Snuff box provenance: Possibly Queen Charlotte; Princess Sophia; passed to Mary, Duchess of Gloucester (d.1857); by whom bequeathed to Princess Mary Adelaide, Duchess of Teck; by whom given/bequeathed to Queen Mary (QMB I, no.283).
Queen Charlotte's personal jewels were divided between her five daughters. Princess Sophia never married. Garrard compiled a 25 page inventory of Sophia's jewels, gold, silver and objets de vertu. These were divided into four. Her sister Princess Mary, Duchess of Gloucester received the amethyst snuff box along with several items of jewellery.
Ok, this is just one possible line for some amethysts to reach Queen Mary from Queen Charlotte.
--Previous Message-- : The Duke and Duchess of Cornwall of York : (later King George V and Queen Mary) toured : the Commonwealth for six months March to : October 1901, visiting Gibraltar, Malta, : Aden, Ceylon, Singapore, Australia, New : Zealand, Mauritius, Natal and Cape of Good : Hope, and Canada. : : The highlight of the tour was the opening of : the first Australian Federal Parliament in : Melbourne 9 May 1901. On the evening after : the formal opening there was a gala : reception, and the dress of the duchess was : described thus in The London Times: : ´The Duchess of Cornwall, who was dressed in : black, wore a tiara and a necklace of : amethysts, which belonged to Queen : Charlotte´. : : The royals were still in mourning for Queen : Victoria, who had died the previous January, : which explain the sombre colour of the dress : and the appropriate amethyst jewels. : : I wonder, however, if you have previously : read of an amethyst tiara (or other amethyst : jewels) from Queen Charlotte? There are not : many amethyst jewels in use today except the : Kent demi-parure. There was an amethyst : tiara which belonged to Queen Mary and was : later sold by a descendant (sometimes : wrongly described as sold by the late Queen : Mother). Others? :