The Scarab found in Riven.
|D'ni Ages, Riven
A Tree falls; a page arises.
A scarab is captured; ink is released.
Life is taken; an Age is given.— D'niGuild.com
It can be assumed that the scarab was native to Garternay, birthplace of the Art, and that D'ni and Ronay Writers wrote them into many other Ages. Catherine notes in her journal that Gehn specifically wrote the elements necessary for creating Books and Ink into the Age of Riven, if not every Age he ever wrote. This is why the scarab is present in Riven. Given Gehn's habit of copying from other books, the same Scarab can probably be found in other Ages. As of yet though, we have no records of their existence outside Riven.
Gehn built the Gate Room on Temple Island as a sort of tribute to the Art. The columns represent the trees necessary for creating books, and on the columns are large replicas of the scarab, representing the ink. The inkwell Gehn used for writing, found in Age 233, is in the shape of a scarab.
In Ahyoheek, a D'ni game similar to "Rock, Paper, Scissors", one of the three symbols a player may play is a scarab.
In Gahreesen, the Guild of Maintainers used beetles that could sense ink as a security measure to detect unauthorized linking books. It's unknown if these are the same kind of beetles used in the ink making process, or if they're related in some way.
In any case, the exact process of making Ink was a closely guarded secret of the Guild of Ink-Makers. It is said that they never wrote it down, and passed on the formula through oral tradition for thousands of years. While trapped on Riven, Gehn struggled for a long time to recreate the Ink formula by himself.