And the character of the cliffs was changing.

Veins of quartz shone under the metallic plating like cut crystal, like cloudy opals; here was a splash of vermilion, there a patch of amber; bands of pallid ochre stained it.
My gaze was caught by a line of inky blackness in the exact center of the falling floor.

So black was it that at first glance I took it for a vein of jetty lignite.
It widened.

It was a crack, a fissure.

Now it was a yard in width, now three, and blackness seemed to well up from within it, blackness that was the very essence of the depths.