Earth’s plate boundaries may nurture diamond formation

High-pressure, high-temperature experiment supports idea about gems’ origins

DEEP DEVELOPMENT  Diamonds (dark grey) begin to form from minerals containing iron and magnesium (white) and from carbon-oxygen compounds called carbonates (light grey) in a scanning electron microscope image. 

Y.N. Palyanov et al/PNAS 2013

Boundaries between tectonic plates may make ideal diamond nurseries, according to an experiment that mimics conditions deep in the Earth.