Two hundred years in the future, in a fully colonized solar system, police detective Josephus Miller (Thomas Jane), who was born in the asteroid belt, is given the assignment to find a missing young woman; Julie Mao (Florence Faivre).
Perlite is made from a mined volcanic glass of the same name. As a raw material it contains water, trapped by the rapid cooling of lava. The moisture vaporizes explosively when heat is applied.
Similarly, what about coquina...a rock made entirely of seashells? Shells are made of mineral matter, but they aren't minerals any more than teeth are. Finally, we have the exception of obsidian. Obsidian is a rock glass, in which little or none of its material has gathered into crystals. It is an undifferentiated mass of geological material, rather like slag but not as colorful.