The writhing serpents in Sylvie Corbelin’s wildly imaginative Pythie ring recall the extraordinary hair ornament from Southern India, on display as part of the Bejeweled Treasures Al Thani exhibition at the V&A, in which diamond-encrusted serpents, representing procreation and fertility, wrap themselves around a central ruby, before spilling down a woman’s braid in diamond leaves and pearls. Here,…