In twin papers published today by American Mineralogist and sponsored in part by NASA, Carnegie scientists Robert Hazen and Shaunna Morrison detail a novel approach to clustering (lumping) kindred species of minerals together or splitting off new species based on when and how they originated.

Once mineral genesis is factored in, the number of "mineral kinds"—a newly-coined term—totals more than 10,500, a number about 75% greater than the roughly 6,000 mineral species recognized by the International Mineralogical Association (IMA) on the basis of crystal structure and chemical composition alone.

"This work fundamentally changes our view of the diversity of minerals on the planet," says Dr. Hazen, Staff Scientist with the Earth and Planets Laboratory, Carnegie Institution for Science, Washington DC.

80% of Earth's minerals were mediated by water

"For example, more than 80% of Earth's minerals were mediated by water, which is, therefore, fundamentally important to mineral diversity on this planet. By extension, this explains one of the key reasons why the Moon and Mercury and even Mars have far fewer mineral species than Earth."

"The work also tells us something very profound about the role of biology," he adds. "One third of Earth's minerals could not have formed without biology—shells and bones and teeth, or microbes, for example, or the vital indirect role of biology, such as by creating an oxygen-rich atmosphere that led to 2,000 minerals that wouldn't have formed otherwise."