During a nanomineralogy investigation of the
Allende CV3 carbonaceous chondrite, a new Ti-rich silicate,
Ca_3Ti_2(SiAl_2)O_(12) with the Ia-3d garnet structure, was identified
in the Type B1 Ca,Al-rich inclusion (CAI) Egg-3. Field-emission
SEM with EDS and electron back-scatter diffraction and electron
microprobe were used to characterize the composition and structure.
Synthetic Ca_3Ti_2(SiAl_2)O_(12) is not reported. We present here
the natural occurrence of Ca_3Ti_2(SiAl_2)O_(12), as a new alteration
silicate in a CAI, and discuss its origin and significance for secondary
processes. The mineral is currently under review by the
Commission on New Minerals, Nomenclature and Classification
of the International Mineralogical Association (IMA 2013-029).
It is a new member of the schorlomite group in the garnet supergroup
