Petra, meaning stone, takes its name from skandalopetra, the ancient Greek art of freediving.  Brave divers would descend into the depths without equipment, holding a weighted stone tethered by rope, before being drawn back to the boat.  Suspended from 8mm keshi studs, fine 18K yellow gold chains set with diamonds hold 12mm triangle-shaped Australian South Sea pearls, evoking the skandalopetra stones and ropes that once connected divers to vessels.