Silcrete

Silcrete are a group of minerals that occur off -setting, silica. They act as conglomerates to form crust. There are but colloquially all siliceous crusts understood below. The name comes from engl. silica for silica and concrete for concretion together. The term was first proposed in 1902 by Lamplugh.

Occurrence

They come in Australia are common. You usually find it in the arid parts of the continent, as Härtling.

Formation

Silcrete occur as silicate incrustation when silicified to the reaction of ortho silicic acid with water, the resulting solid silica. This happens sometimes when accumulate mineral subsoils. The silica occurs first released on thereafter to stiffen to a hard cement.

The procedure is similar to the quartzite.

Properties

Silcrete are hard, heat supply, they can be even harder. Their color is reddish.

Use

In Australia silcrete are often used by the Aborigines as tools. In Africa, two tools were found from Silcreten that are 60,000 and 80,000 years old.

Silcrete also be used for road design.