According to Carnegie's Robert Hazen as of right now there are no more than 420 minerals on Earth today. This is about 8 percent of nearly 5,000 species on Earth. Hazen believes that most of these 420 minerals of the Haden Eon formed from magma. Thousands of mineral species known today are the direct result of growth by living organisms, such as shells and bones, as well as life's chemical byproducts, such as oxygen from photosynthesis. Lithium, beryllium, and molybdenum appear to have taken atleast a billion years to form so they are excluded from the times of lifes origin. Several questions remain unanswered and offer opportunities for further study of the paleomineralogy of the Hadean Eon. For example, the Hadean Eon differs from today in the frequent large impacts of asteroids and comets -- thousands of collisions by objects with diameters from a mile up to 100 miles. Such impacts would have caused massive disruption of Earth's crust, with extensive fracture zones that were filled with hot circulating water. Such hydrothermal areas could have created complex zones with many exotic minerals. Hazen believes that Mars is just like Hadean Earth and may be limited to only about 400 minerals also.
The magnesium silicate forsterite was one of the most abundant minerals in the Hadean Eon, and it played a major role in Earth's near-surface processes. The green color of this mineral (which is also known as the semi-precious gemstone peridot, the birthstone of August) is caused by small amounts iron. The iron can react with seawater to promote chemical reactions that may have played a role in life's origins. (Credit: Robert Downs, University of Arizona, Ruff Project)
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