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.
The pumice stone is extremely rough and very porous and surprisingly light when picked up. This is the only stone that will actually float on water until becoming waterlogged, at which point it will sink. The mineral makeup of pumice depends on the type of magma that composes the pumice foam. Basalt Minerals Basalt is a gray to black fine-grained volcanic rock that is often the origin of pumice.