Pedra do Tempo is a large-scale installation made out of schist. It is composed of four solid pieces of schist, two laid on the floor as a base, and two standing, sculpted from the inside. Granulated sand dust passes through the elevated stones, one time only, transforming the installation into an ephemeral performance: a type of hourglass clock speaking of a time that has already passed, of resources that have been exhausted. A statement about the fragility of natural ecosystems and the depletion of their resources over time, further reflected by the fragility of this type of stone itself, which is easily chipped and broken, as opposed to other, harder and more compact ones, like granite or marble.

Pedra do Tempo, by Carla Juaçaba

We know nothing about the minutes that pass.
Analog and digital clocks always seem to be lying about the passage of time, even because they fail at times.
However, the hourglass is real: time passes visibly. And it stops. As life stops, as resources end.
But stone remains stone.
Even when it becomes dust.