What are acidic igneous rocks?

Appearance: Light coloured, medium- to coarse-grained intrusive igneous rocks with more than 20% of quartz. Within feldspars, the Na-rich plagioclase prevails over K-feldspar (orthoclase). The mafic minerals are represented by amphibole, pyroxene and biotite. This is the intrusive equivalent of dacite. read more

Acid igneous rocks, such as granite, are less dense and are lighter in colour than basic rocks. Based on place and time taken in cooling of the molten matter, igneous rocks can be divided into Plutonic and Volcanic rocks. read more

Igneous rock (derived from the Latin word ignis meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. read more

Igneous rocks are primary rocks and other rocks form from these rocks. Igneous rocks can be changed into sedimentary or metamorphic rocks. The fragments derived out of igneous and metamorphic rocks form into sedimentary rocks. read more

Appearance: Light coloured, medium- to coarse-grained intrusive igneous rock containing more than 20% quartz and the amount of alkali feldspars (orthoclase) exceeds that of the plagioclase. The mafic minerals are usually biotite, but amphibole and pyroxene could also occur. read more