Yet another discovery tonight in the wall reef. This rock has been stationary for almost a year now and it looks like it's growing into the back wall. The dark looking matter is actually translucent and like a thick gel. I've felt it under some other rocks but not seen it spread like this in direct light and get coralline encrusting on it. The actual rock structure touching the wall is about 1/2 that mass, like a cone point I used to prop it away from the wall.