Scarcity raises ethical questions about deepwater corals

Not all treasure is underground. For centuries, jewellers have prized precious materials from organic sources. Pearls, of course, and the mother-of-pearl secreted by shell creatures for protection. And also from the sea, glorious coral, ranging from fossil coral to rich red corallium rubrum, along with the iridescent rainbow beauty of ammolite from the fossilised shells of ammonites. Amber, the fossilised resin of ancient trees, is also found in the ocean. Jet is another organic gemstone from ancient trees, found in coastal cliffs as a compressed layer of the decayed wood.

All of these, at some point in history, have been prized as protective talismans. In more recent times, jet was the preferred material for mourning jewellery; such pieces, especially if used by European royalty, are collector’s items.