Diamond Rain

Science Daily: Scientists create 'diamond rain' that forms in the interior of icy giant planets - SLAC's X-ray laser and Matter in Extreme Conditions instrument allow researchers to examine the exotic precipitation in real-time as it materializes in the laboratory

summary - In an experiment designed to mimic the conditions deep inside the icy giant planets of our solar system, scientists were able to observe 'diamond rain' for the first time as it formed in high-pressure conditions. Extremely high pressure squeezes hydrogen and carbon found in the interior of these planets to form solid diamonds that sink slowly down further into the interior.