The delicacy of Belle Epoque jewellery is unlike almost anything else. The period saw the emergence of white metals and finely detailed metal work as platinum grew in popularity.  This piece by Faberge is described this way by Bentley & Skinner:

An important turn-of-the-century Faberge aquamarine and diamond pendant, the pendant comprising an oval faceted aquamarine, within a diamond-set border, with three diamond foliate drops, with diamond surmount and chain, Purchased by dowager Empress Maria Fedorovna of Russia 28/7/12 for 260 roubles.  Was a gift to Augusta Marie Utke Ramsing 1875-1959 who was lady-in-waiting to Princess Margrethe of Denmark, sister of Tsarina of Russia, & by descent to present owner. Circa 1895

It is available on their web site for £135,000.