‘Sophie, come and look,’ Mum calls. I sulk, go to the window. Pretend to give a shit about jewellery. The opals are arranged on velvet cloth, shimmering under the hot beam of an office lamp. Occurs in the fissures of almost any rock, the note card says, most commonly in limonite, marl, basalt, rhyolite. Before they’re mined, opals run deep underground, seamed through the earth like irregular veins. These stones look dead on the black cloth, as if prepared for reburial.