Felsic

Felsite are generally bright igneous or metamorphic rocks, which mainly consist of quartz and feldspar, ie felsic minerals and a density of less than 3 g / cm ³.

The term felsite is a summary of the words feldspar and silica, eluting with silicate quartz here is meant. The corresponding adjective is felsic. Since quartz from silica, chemically incorrect often referred to as silicic acid, also the expression of acidic rocks is often used for felsite.

The adjective felsic also stands for a fine-grained to dense and marked morphological grain without special training structure felsic rocks.

Felsic glass, such as Obsidian, were in cultures in which the metal processing was not known, important raw materials for tools and weapons.