Vermiculite is a natural, non-toxic mineral, expands under high temperature minerals. It is a relatively rare mineral, is Portland. The crystal structure of the monoclinic system, from the shape it looks like mica. Vermiculite is a certain degree of hydration generated when the granite. It is usually produced with asbestos at the same time. Since vermiculite has ion exchange capacity, soil nutrients it has great effect. In 2000 the world total output of more than 500,000 tons of vermiculite. The main producing countries are China, South Africa, Australia, Zimbabwe and the United States.
Vermiculite is a mineral with montmorillonite clay similar for the layered structure of silicates. Generally biotite weathering by hydrothermal alteration or become. It sometimes looks like coarse biotite occurs (this is the illusion of vermiculite and biotite), and sometimes have to be a soil-like subtle. The vermiculite is heated to 300 ℃, it can expand 20-fold and bend. This time, a bit like a leech vermiculite (commonly known as leech leech), so it has such a name. Vermiculite is generally brown, yellow, dark green, like oil sheen. Heated they become gray. Vermiculite can be used as building materials, absorbents, fire insulation materials, machinery lubricants, soil conditioner and so on.