The Carbon Mineral Challenge was set in motion by DCO at the 2015 AGU Fall Meeting, with the goal of finding at least some of Earth’s 145 “missing” carbon minerals. The Challenge built on the work of DCO Executive Director Robert Hazen (Carnegie Institution for Science, USA) and colleagues, who used data science and statistical methods to look at the known minerals on Earth and predict those that should exist but remained undocumented.
From the outset, DCO early career scientist and study co-author Daniel Hummer pioneered the Challenge, working with an international advisory board to seek out sources of new minerals. Hummer (Southern Illinois University, USA) also worked with collectors and curators to look for signs of un-documented minerals in existing collections. A recent article in The Australian Journal of Mineralogy, authored by Hummer, summarizes the success of the Carbon Mineral Challenge.

At its conclusion, mineral sleuths from around the globe had identified 31 new carbon-bearing mineral species during the Challenge. The proportion of newly discovered carbon-containing minerals increased from an average of 3.6% before the Challenge to an average of 5.0% during the Challenge, which represents a statistically significant increase in the rate of discovery of carbon minerals.
Hummer and colleagues celebrated the official conclusion of the Challenge with a session at the 2019 meeting of the Geological Society of America, which took place in Phoenix, USA, from 22–25 September 2019. During the session, Hummer presented an overview of the Challenge, and Robert Hazen presented on the ecology and classification of carbon minerals.

Several participants in the Challenge also presented on their mineral discoveries. Jordi Ibanez-Insa presented on abellaite, the first new carbon mineral ratified during the Challenge that was also predicted by Hazen and colleagues. Travis Olds shared his discovery of the carbon-bearing mineral ewingite, a uranyl carbonate mineral that now holds the record for the most structurally complex mineral on Earth.
The celebration continued with a dinner at Mancuso's restaurant in downtown Phoenix, which was attended by members of the mineral ecology research team, Carbon Mineral Challenge advisory board members, and participants of the Challenge.
“I’m thrilled the Carbon Mineral Challenge was such a success,” said Hummer, after the meeting. “It’s a great indication that future efforts aimed at targeted mineral discovery would be worthwhile endeavors moving forward, and a great way to engage citizen scientists in mineralogy.”
Main image: Ewingite, currently the most structurally complex mineral known using the information content method given by Krivovichev (2012), at 12230 bits per unit cell. Its rarity appears to be due to a very narrow pH and compositional range during formation that is only found in the Plavno mine. Credit: Travis Olds