Newly Discovered Mineral Provides Clues To Evolution Of Solar System
June 27, 2012

Newly Discovered Mineral Provides Clues To Evolution Of Solar System

Lawrence LeBlond for

A previously unknown mineral has been found in a meteorite that fell to Earth in 1969, according to a Caltech geologist who has been studying the meteoric sample since 2007, and who has also found eight other new minerals in the sample.

The Allende meteorite was among thousands of meteorites that lay scattered about the state of Chihuahua, in Mexico, after a meteor exploded over the region in 1969. More than 40 years later, the meteorite is providing researchers with a rich source of information about the early days of our solar system.

The newly discovered mineral -- panguite -- was named by geologist Chi Ma at California Institute of technology (Caltech) after Pan Gu, a giant from ancient Chinese mythology who established the world by separating yin from yang to create the earth and sky. The International Mineralogical Association´s Commission on New Minerals, Nomenclature and Classification accepted the mineral and its name.

Ma and his colleagues believe that panguite is among the oldest minerals found during the creation of our solar system, nearly 4.6 billion years ago. They will publish their findings in the July issue of the journal American Mineralogist; the online edition is available now.

The discovery is “especially exciting” since panguite is “not only a new mineral, but also a material previously unknown to science,” said Ma, a senior scientist and director of the Geological and Planetary Sciences division´s Analytical Facility at Caltech.

The Allende meteorite is the largest carbonaceous chondrite ever found on the planet and is considered by many the best-studied meteorite to date. Through Ma´s research, he and his team were able to glean nine new minerals, including panguite, from the meteorite. Some of these new finds include allendeite, hexamolybdenum, tistarite, and kangite.

“The intensive studies of objects in this meteorite have had a tremendous influence on current thinking about processes, timing, and chemistry in the primitive solar nebula and small planetary bodies,” said coauthor George Rossman, the Eleanor and John R. McMillan Professor of Mineralogy at Caltech.

Panguite´s primordial nature means it was actually around before the Earth and other planets formed, and offers scientists unique clues about the conditions in the cloud of gas and dust that were the building blocks of our solar system.

The mineral´s chemical name is (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, meaning that it contains some familiar elements (oxygen, magnesium, aluminum) as well as exotic ones (zirconium and scandium). The researchers believe zirconium is a key element in deciphering the environment that existed before and during the formation of the solar system.

Ma and colleagues observed panguite under a scanning electron microscope in an ultra-refractory inclusion embedded in the meteorite. Ma noted that refractory inclusions are among the first solid objects formed in the solar system. He further noted that “refractory” refers to the fact that the inclusions contain minerals that are stable at high temperatures and in extreme environments, which attests to their likely formation as primitive, high-temperature liquids produced by the solar nebula.

These investigations are “essential to understand the origins of our solar system,” concluded Ma.