Compared to other rocky planets in our solar system, Earth is missing something. Some parts of its crust, or outer layer, have a lot less iron (Fe) than expected. A new study suggests the element may have been stolen. The likely culprit: a sparkly red mineral called garnet.
Scientists think garnet absorbs iron atoms—the smallest unit of an element—as the mineral forms in magma pools deep underground. Mystery solved? More work is needed to say for sure, says Ming Tang, a geochemist at Rice University in Texas who ran the recent study. “There is always uncertainty in science,” he adds. “That’s part of the fun.”