Geologists rely on tiny crystals of the mineral zircon to understand the timing of key events in Earth's early days, like the rising of continents and the emergence of oceans.
To peer into Earth's deep time, meet a hardy mineral known as the Time Lord wlrn.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from wlrn.org Daily Mail and Mail on Sunday newspapers.
Using equipment in a new laboratory funded by Penn State, geoscientists are able to measure the age of rocks using an advanced mineral-dating process that analyzes the atomic proportions of uranium and lead in the mineral zircon.