Researchers picked oyster, mussel and cockle shells off Irish beaches, crushed the 3 kinds of shell into grains, and dropped them into water carrying rare earth metals at concentrations similar to badly polluted industrial runoff. The oyster grains took up as much as roughly 1.5 grams of metal for every gram of shell.
A single gram of crushed oyster shell pulled in up to around 1.5 grams of rare earth metal,…