There's a lot of pressure, the weight of the overlying rock bearing down, so that combination of high temperature and high pressure is what's necessary to grow diamond crystals in the Earth.

Crystals -- from sugar and table salt to snowflakes and diamonds -- don't always grow in a straightforward way. Researchers have now captured this journey from amorphous blob to orderly structures.

To better understand them, Chong Zu, PhD, assistant professor of physics at WashU and one of the study’s authors, compares time crystals to diamonds or quartz, whose shape and shine come from ...