Mirrorbeings (also Mirrorsouls) are the intelligent inhabitant of Terrafirma. They are like humans in many respects. They are composed of three parts: Sand, Glass, and Silver and bound by cords of Fire.
The Sandbeing is the mirrophysical part of a Mirrorsoul. It is world-conscious. This has been severely Corrupted.
The Glassbeing is the bridge between the mirrophysical and aethereal. It is self-conscious. This is who the Mirrorbeing is.
The Silverbeing is the purest part of a Mirrorbeing. It is however dead until Sealed. It is aethereal and Being-conscious.
The Cords of Fire bind these three parts together.