Calcium–aluminium-rich inclusion
A calcium–aluminium-rich inclusion or Ca–Al-rich inclusion (CAI) is a submillimeter- to centimeter-sized light-colored calcium- and aluminium-rich inclusion found in carbonaceous chondrite meteorites. The first high-precision radiometric datings of CAIs involved four samples examined through the Pb–Pb chronometer, yielding a weighted mean age of 4567.30 ± 0.16 Ma.
Source: Wikipedia — Calcium–aluminium-rich inclusion (CC BY-SA 4.0)