New knowledge are always fascinating, some knowledge more than others.
Enlarged backscatter image showing the area where panguite crystals (type material) occur with smaller Zr-rich panguite in davisite (Fig. 1). The cross marks where the EBSD pattern (shown in Fig. 3) and the synchrotron micro-diffraction data were collected. The mottled appearance of the davisite mostly reflects differences in Sc concentrations. (From refernced paper)
Researchers has worked on a newly discovered titania mineral since 2007 and has now identified and described it in a newly publicised paper. The new mineral has been named “Panguite” and has been formed 4567 Ma, this means that this mineral formed before the planets formed and are therefore one of the oldest minerals found. Not surprisingly it has been identified in a chondrite named “Allende CV3 carbonaceous chondrite” which fell to Earth in 1969. It has also been confirmed in two other chondrites of different types. In the Allende chondrite it was found as inclusions in an olivine inclusion, in contact with and associated with davisite. This has been confirmed from the other two occurrences. The researches conclude that it is a widespread but rare mineral in carbonaceous chondrites, and are closely related to davisite.
Several properties and the chemical composition was of course measured. The chemical formula are expressed as (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3 or more exact as [(Ti0.79Zr0.16Si0.04)4+∑0.99(Sc0.20Al0.20Y0.06V0.02Cr0.01)3+∑0.49(Mg0.18Ca0.08Fe0.03)2+∑0.29]∑1.77O3. Most physical properties was not measures due to its small size, 0.5-2 μm, but it is opaque with a density of 3.746 g/cm3 and is not fluorescent. Two distinct chemical composition was noticed, where one was higher in Zr and Y. Crystallographically panguite has a primitive orthorhombic lattice structure in the Pbca space group. The unit dimensions are: a = 9.781(1), b = 9.778(2), c = 9.815(1) Å.
This mineral represent a completely new material since it has never before been identified or synthetically produces. This also mean that the exact prerequisites for its formation are unknown. It is probable that panguite formed in an oxidizing environment after which davisite nucleated opportunistically on the panguite crystals in a much more reducing environment.
Chi Ma, Oliver Tschauner, John R. Beckett, George R. Rossman, and Wenjun Liu (2012). Panguite, (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, a new ultra-refractory titania mineral from the Allende meteorite: Synchrotron micro-diffraction and EBSD American Mineralogist American Mineralogist DOI: 10.2138/am.2012.4027