New primitive mineral found in Allende meteorite

The Allende meteorite impacted in the Mexican state of Chihuahua in 1969. More than 40 years later, the meteorite continues to help scientists better understand the early stages of our solar system’s evolution.

Indeed, researchers from the California Institute of Technology (Caltech) recently 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, a giant from ancient Chinese mythology who is said to have 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,” explained Chi Ma, director of the Geological and Planetary Sciences division’s Analytical Facility at Caltech.

According to Ma, 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 – 9 new minerals, including panguite, have been found in the Allende meteorite. Some of those new finds include the minerals 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 Professor George Rossman.

Panguite was first observed 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.

As Ma notes, 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 added.