👉 milleporite is a type of volcanic rock that consists of numerous tiny, irregularly shaped crystals or pebbles. It is often found in volcanic areas and can be found on the surface of mountains or in caves. Milleporites are typically small and irregular, with their size varying from several millimeters to tens of meters. They have a distinctive gray coloration due to the presence of iron oxide, which gives them an interesting appearance. Milleporites were once considered a rare