The Allende meteorite that exploded over the skies of Mexico in 1969 is the source of a newly discovered mineral, panguite.
More than 40 years after crashing to Earth, this meteorite is still a spring of information — a previously unknown mineral embedded in it was recently identified by scientists from the California Institute of Technology (Caltech).
Named panguite, the mineral is a new form of titanium oxide. The name comes from Pan Gu, “the giant from ancient Chinese mythology who established the world by separating yin from yang to create the earth and the sky.”
“Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science,” says Chi Ma, a senior scientist and director of the Geological and Planetary Sciences division’s Analytical Facility at Caltech and corresponding author on the paper.
The Allende meteorite that the mineral panguite was found in is the largest carbonaceous chondrite ever found on Earth and is probably the best-studied meteorite in human history. Carbonaceous chondrites are a very diverse class of primitive meteorites that formed early in the history of the solar system.
The ongoing nanomineralogy investigation of the Allende meteorite has, so far, found nine new minerals, including panguite. Some of the new ones include allendeite, hexamolybdenum, tistarite, and kangite. Nanomineralogy is the study of nano-scale particles of minerals and the features within those minerals.
“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,” says coauthor George Rossman, the Eleanor and John R. McMillan Professor of Mineralogy at Caltech.
Panguite was first seen “under a scanning electron microscope in an ultra-refractory inclusion embedded in the meteorite. Refractory inclusions are among the first solid objects formed in our solar system, dating back to before the formation of Earth and the other planets. ‘Refractory’ refers to the fact that these 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.”
According to the study authors, research on panguite and other newly discovered refractory minerals are continued in order to learn more about the conditions under which they formed and later changed. “Such investigations are essential to understand the origins of our solar system,” he says.
A study about this new discovery, and the properties of the new mineral, will be published in the July issue of the journal American Mineralogist.
Additional authors on the paper, “Panguite, (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, a new ultra-refractory titania mineral from the Allende meteorite: Synchrotron micro-diffraction and EBSD,” are John R. Beckett, senior research scientist at Caltech; Oliver Tschauner from the University of Nevada–Las Vegas; and Wenjun Liu from the Argonne National Laboratory. The study was supported through grants from the National Science Foundation, the U.S. Department of Energy, and NASA’s Office of Space Science.