The stone colour

Making modifications, it didn't take long to find a second room, in the opposite direction, and this time a little up. There was no monster; the room was smaller, like a natural crack, between walls of something similar to reddish salt. He slid to the bottom until he found a singular stone, this time black.

There were no surprises, or anything like that, just patience in handling the 50 torches.

Ikky didn't know how it worked exactly, but he was determined not to give up so easily, but he wasn't willing to give up. Let's see, Ikky thinks, you don't know anything about geology, but think... The two rooms were in different strata and types of stone.

If that puzzle had several rooms there had to be a way to achieve something. What did the stones represent? It was clear that they weren't gems, they were just colored stones, one blue and one black...