[meteorite-list] Caltech Scientists Find New Primitive Mineral in Allende Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 27 Jun 2012 09:47:04 -0700 (PDT)
Message-ID: <201206271647.q5RGl4xr018171_at_zagami.jpl.nasa.gov>


Caltech Scientists Find New Primitive Mineral in Meteorite
California Institute of Technology
June 26, 2012

PASADENA, Calif. - In 1969, an exploding fireball tore through the sky
over Mexico, scattering thousands of pieces of meteorite across the
state of Chihuahua. More than 40 years later, the Allende meteorite is
still serving the scientific community as a rich source of information
about the early stages of our solar system's evolution. Recently,
scientists from the California Institute of Technology (Caltech)
discovered a new mineral embedded in the space rock - one they believe to
be among the oldest minerals formed in the solar system.

Dubbed panguite, the new titanium oxide is named after Pan Gu, the giant
from ancient Chinese mythology who established the world by separating
yin from yang to create the earth and the sky. The mineral and the
mineral name have been approved by the International Mineralogical
Association's Commission on New Minerals, Nomenclature and
Classification. A paper outlining the discovery and the properties of
this new mineral will be published in the July issue of the journal
American Mineralogist, and is available online now.

"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

The Allende meteorite is the largest carbonaceous chondrite - a diverse
class of primitive meteorites - ever found on our planet and is considered
by many the best-studied meteorite in history. As a result of an ongoing
nanomineralogy investigation of primitive meteorites - which Ma has been
leading since 2007 - nine new minerals, including panguite, have been
found in the Allende meteorite. Some of those new finds include the
minerals allendeite, hexamolybdenum, tistarite, and kangite.
Nanomineralogy looks at tiny particles of minerals and the minuscule
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 observed first 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 Ma, studies of panguite and other newly discovered
refractory minerals are continuing in an effort to learn more about the
conditions under which they formed and subsequently evolved. "Such
investigations are essential to understand the origins of our solar
system," he says.

Additional authors on the American Mineralogist paper, "Panguite,
(Ti^4+ ,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.

Deborah Williams-Hedges
debwms at caltech.edu <mailto:debwms at caltech.edu>
Received on Wed 27 Jun 2012 12:47:04 PM PDT

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