âºâº Definition: Ton. The short ton is a unit of mass equal to 2000 lb (exactly 907.18474 kg). In the United States it is often called simply ton without distinguishing it from the metric ton (or tonne) and the long ton rather, the other two are specifically noted.
Pumice is a light-colored, extremely porous igneous rock that forms during explosive volcanic eruptions. It is used as aggregate in lightweight concrete, as landscaping aggregate, and as an abrasive in a variety of industrial and consumer products.he abundant vesicles in pumice and the thin walls between them give the rock a very low specific gravity. It typically has a specific gravity of less than one, giving the rock an ability to float on water.
pumice The type of igneous rock that floats is called Pumice. It isn't lighter than other rocks, just less dense because it has lots of very small air bubbles trapped in it. Y â¦ ou can see these if you look at the exterior of the rock. A non porous rock is a rock which has interlocking grains so water can't get into it. A porous rock is like a sponge and a non porous rock is like a stone.