Coral is classified as an organic gemstone, separate from the larger mineral category, meaning that it is derived from animal or plant life, a group which also includes pearls and amber. More specifically coral is a ‘calcareous concretion’, and is in actuality the skeleton of the sea animal coral, composed of calcium carbonate. There are many types of corals, but the varieties used in jewellery typically form in warm salt water including the Mediterranean Sea, the Red Sea and the waters of Asia, Australia and the Caribbean.
Perhaps the most famous source of coral, at least with regards to Western jewellery, is the Mediterranean. The seaside village of Torre del Greco, at the foot of Mount Vesuvius on the Bay of Naples, has been the centre for the fashioning of coral since the fifteenth century. The height of coral production, when coral jewellery was at the apex of its vogue, was in the 1880s when there were over forty workshops in the town.
Coral has long been associated with protective powers, and particularly in Mediterranean cultures was believed to ward off the evil eye. For this reason it was often used in children’s jewellery as well as toys, such as rattles and teething devices. It was also thought to banish tension and fear, and to promote positive social interactions. Still today in Italy it is common to see ‘cornicello’ pendants made of polished segments of red coral.
The coral used in jewellery is typically red, pale pink or peach, but it also forms in white, black, brown and, though quite rare, in blue. Usually it is polished to a shine, however peach coral is often left matte, and is known in the trade, rather charmingly, as ‘angel skin’. In any shade, it is a lovely and apropos summertime gemstone.