Smithsonian Magazine covers Bob Hazen and the Deep Carbon Observatory's Carbon Mineral Challenge

We are missing aat least 145 carbon-bearing minerals and you can help find them. Smithsonian Magazine covers the Carbon Mineral Challenge, launched by Robert Hazen and Daniel Hummer at The American Geophysical Union's fall meeting, which is asking rock enthusiasts around the world to hunt for the undiscovered forms of this common element. More