Next to the historical gems is the Great Ruby, the size of an egg. The widow of King Charles IX of France gave it to her brother. King Rudolph of Bohemia. During the Thirty Years' War (1618-48) the Caesar Ruby, as the gem was then called, was taken from Prague to Stockholm. On a visit to St. Petersburg in 1777 King Gustavus III of Sweden presented the Great Ruby to the Russian Empress Catherine the Great. Soviet specialists have established that this gem is not a ruby, but a tourmaline. Jewellers skilfully supplemented the natural shape of the gem with sheets of gold covered with green enamel and a bifurcated stalk.

Aigrette in the form of a fountain

     Among the eighteenth-century jewels on show is the Great-Bouquet. worn on the belt or corsage. Made of Brazil diamonds and Columbia emeralds, the bouquet is most elegant in form and rich in colour. The illusion of live colour was created by the use of a special fastener for the gems.
     The Small Diamond Bouquet, a wreath-shaped diadem and ear-rings which form a set, is remarkable for its rich colours and sumptuous patterns. The aigrette of diamonds with large blue sapphires and diamond jets is most original. It was used as a female hair ornament.

Tourmaline

     Among the rare items of jewellery note the esclavage bow and earrings with red spinels set in diamonds, the work of a St. Petersburg master in 1764, and also the Cornucopia hair pin by Louis-David Duval. This eminent jeweller showed remarkable inven-tiveness and skill in making use of a gem's natural qualities. It is highly likely that the diamond hair pins in the form of baskets of roses are also his work. The openwork diamond hair pins in the form of hair ribbons were made with great artistic taste by another well-known jeweller, Jeremie Poz-ier, a Swiss who worked in Russia for almost forty years.
     Nineteenth-century exhibits include the diadem of Empress Elizabeth, the wife of Alexander I, made of 175 brilliant-cut and 1,200 rose-cut diamonds.
     The aigrette—port-bouquet, a female hair ornament, is beautiful and elegant. The intricately curving diamond branches have blossoms and buds of Ceylon sapphires bordered with diamonds. The gold tie pins adorned with very rare pink and pale blue diamonds are most impressive.