From Halopedia, the Halo wiki
The Age of Abandonment, also called the First Age of Abandonment, is the name given to the first period of Covenant history, even though it technically predates the formation of the Covenant. This age refers to the time from 2200 BCE, which marked the start of the Stoic-Reformist conflict, and 2100 BCE, when the Forerunner Dreadnought left Janjur Qom. In the ceremonial Progression of the Ages, this age is represented by an obsidian stone.
During the ritual, the appropriate dialogue is as followed:
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