Rocks formed by the crystallization of lava or magma. 25 Rock forming minerals make-up most of the earth's crust. The most abundant minerals of the earth's crust are silicate ,SiO 2, and orthoclase, KAlSi 3 O 8 . The major mineral groups of the earth's crust are given in Table 43.1. Native Elements Copper Cu Sulfur S Secondary Minerals are formed by alteration of the parent mineral.
Evaporites are water-soluble salts that precipitate from solution in arid conditions.
Na 2 SO 4 Gypsum CaSO 4 2H 2 O Volcanic Subliminates are minerals that condense near the mouths of volcanoes and fumaroles. Elemental sulfur is an example of a sublimate. Igneous, s edimentary and m etamorphic r ocks are constantly being transformed from one type of rock into another. The earth's crust, mantle and surface can be considered a giant recycling machine, converting the matter that makes up rocks into new rocks. Since the matter on the earth is neither created or destroyed, it is constantly being transformed and redistributed from one rock type into another.