What type of igneous rock is felsic?
Felsic rocks are igneous rocks that are rich in feldspar and silicon. The word ‘felsic’ was made up from parts of those words. Because they are made of lighter elements, they tend to be more buoyant than mafic rocks, which are rocks high in magnesium and iron, like basalt. Granite is the most common felsic rock.
What types of rocks are in the felsic family?
Felsic rocks are usually light in color and have specific gravities less than 3. The most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars (albite-rich).
What are the four main felsic minerals in igneous rocks?
The felsic minerals include quartz, tridymite, cristobalite, feldspars (plagioclase and alkali feldspar), feldspathoids (nepheline and leucite), muscovite, and corundum. Because felsic minerals lack iron and magnesium, they are generally light in colour and consequently are referred to as such or as leucocratic.
Is Obsidian a felsic rock?
Though obsidian is usually dark in color, similar to mafic rocks such as basalt, the composition of obsidian is extremely felsic. Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% by weight or more. Crystalline rocks with a similar composition include granite and rhyolite.
Where are felsic rocks found?
crust
Felsic magma usually originates in the crust or by the shedding of mafic minerals as magma rises through the crust. The igneous texture tells us how the magma cooled and solidified.
Is pumice mafic or felsic?
Pumice is a low-density, light-colored felsic volcanic rock.
What are some examples of igneous rocks?
Examples of Igneous Rocks: 1. Pumice Stone Pumice stone is found near the site of a volcanic eruption which sent rock and molten lava to the… 2. Granite Granite is one of the most common rocks on Earth, and is the most common igneous rock. This dense stone is… 3. Obsidian
Why are the edges of igneous rocks sharp?
Most igneous rock forms below the Earth’s surface, but one rock-obsidian, or volcanic glass-forms above the surface. This jet-black glass is actually cooled lava, and due to the way that obsidian breaks, its edges are incredibly sharp.
What happens when magma is forced into rocks?
Magma can be forced into rocks, blown out in volcanic explosions or forced to the surface as lava. The atoms and molecules of melted minerals are what make up magma. These atoms and molecule rearrange themselves into mineral grains as the magma cools, forming rock as the mineral grains grow together.