The Ash

There is a chamber of basalt stone, in the center of which is a long table which runs into one continuous piece with the floor.  On the far side is a massive stone vessel, also part of the chamber.  There was solid matter here once; the hollow place you are standing in was carved out, meaning everything in this room is a single piece of stone molded to purpose.

In the walls are many holes about the size of a human head.  Only a few of them are filled with something that looks like a dull crystal, blue and luminescent, but far more are open than filled, for now is the time of antiquity.

Perhaps it doesn't exist yet, but eventually it will, and it exists always, created or not.

This is the Crucible, where The Ash is formed, and The Ash sleeps.  For now.
Below is added a new feature, a great cauldron, where stone does as it wills, but countless fragments of crystal try to swim thru.