There is so much jewelry in the vaults that these well could be a neglected pair of old earrings. Obviously there has been a survey of the Queen's diamonds for the jubilee exhibit and the book. Maybe Angela Kelly said "Look, ma'am, these are rather nice." And Her Majesty said "Yes, I believe I'll wear those to the Opening of Parliament in May." I hope no tabloid picks that up as truth! But I do think discoveries are possible given what is available. Bequests and gifts are also possible. The Queen Mother could have had these earrings.