Crying obsidian clouds/ fields

These new clouds could be an extremely rare randomly generated structure that takes form of a cloud but instead it's a solid floating rock of crying obsidian or obsidian in a crying obsidian shell. Another thing could be a crying obsidian field, an area on a lava lake that is turned into the new basalt block because the roof over this area is now crying obsidian or instead could be a whole biome with a crying obsidian roof.