floating stones of rameswarm a scientific view

depressurizes rapidly, trapping gas bubbles inside. These bubbles give pumice a very low density, allowing it to float on water.
Volcanic Scoria: Similar to pumice, scoria is a volcanic rock that can contain numerous small air bubbles trapped within its matrix. Although generally denser than pumice, some lightweight scoria can float.
The ability of these stones to float is due to their porous structure, which traps air and reduces their overall density below that of water. Over time, as the trapped air escapes or water permeates the pores, these stones will eventually sink.

more on pumice ( floating stone)
Pumice is a fascinating type of volcanic rock, distinctive for its light weight and ability to float on water, at least initially. some key points about pumice:
e to light gray in color, but variations can include off-white, and shades of pink, green or black, depending on the mine