Of these Rhyolite has the highest silica content.
Rhyolite is felsic. Andesite is intermediate and Basalt is mafic.
They have different compositions. Most igneous rocks fall into a spectrum ranging from mafic (low silica, dominated by iron, magnesium, and calicum) to felsic (high silica, dominated by sodium and potassium) On this scale rhyolite is felsic while andesite is intermediate. Rhyolite is dominated by the presence of quartz, potassium feldspar, and sodium-rich plagioclase. Rhyolite also tends to contain more volcanic glass. Common colors of rhyolite are light gray, white, and pink. Andesite often contains plagioclase with a fiar balance of sodium and potassium. Plagioclase is also a common dominant mineral. Andesite is darker than rhyolite, ranging from gray to almost black.
the most common is granite and rhyolite
Both andesite and basalt are volcanic rocks. Basalt is denser and generally darker than andesite. It has a lower silica content and more iron and magnesium. It most often forms from pahoehoe or a'a lava flows and occasionally scoria cinders. Andesite forms from more slica-rich material and is often found in the form of ash, pumice, or volcanic bombs. It may also sometimes form block lava flows, which are more viscous that a'a or pahoehoe.
Feldspar can be a variety of colors: clear, gray, white, tan, pink, brown, or red.
Both are igneous rocks, formed from the cooling and solidification of magma. Granite is a felsic, intrusive igneous rock, with visible well mixed mineral crystals. Basalt is a mafic, extrusive igneous rock, composed of darker mineral crystals, most of which are not distinguishable without the aid of magnification.
They have different compositions. Most igneous rocks fall into a spectrum ranging from mafic (low silica, dominated by iron, magnesium, and calicum) to felsic (high silica, dominated by sodium and potassium) On this scale rhyolite is felsic while andesite is intermediate. Rhyolite is dominated by the presence of quartz, potassium feldspar, and sodium-rich plagioclase. Rhyolite also tends to contain more volcanic glass. Common colors of rhyolite are light gray, white, and pink. Andesite often contains plagioclase with a fiar balance of sodium and potassium. Plagioclase is also a common dominant mineral. Andesite is darker than rhyolite, ranging from gray to almost black.
Extrusive igneous rock would be found near a volcano. Basalt, andesite, and rhyolite are the most basic types of volcanic rock.
Extrusive igneous rock. To be more specific you have to know the composition of the lava. The most common type is basalt, but other types include andesite, dacite, and rhyolite.
Mt St Helen's eruption of 1980 was a pyrocastic flow diverse lava, ranging from olivine basalt to andesite and dacite). The magma is believed to come from another area laterally located to the east. Magma and rock under the volcano are cool.
the most common is granite and rhyolite
There are rocks that are extrusive (formed quickly on the surface of the earth) or intrusive (formed within the earth under slow cooling). Both types of extrusive or intrusive rocks can vary in composition from mafic (high iron and magnesium content) to silicic (less heavy ions like Fe and Mg, but with more of the lighter elements like Ca, Na, K, etc.). Extrusive rocks range from most mafic to less mafic as such: Basalt, Andesite, Rhyolite (and are all fine-grained b/c they cooled quickly). Intrusive rocks that cool more slowly and have larger crystals range from most mafic to less mafic as such: Gabbro, Diorite, Granite. Basalt and gabbro have a similar composition, just the crystal size differs from different cooling rates (same for rhyolite and granite).
Most viscous Felsic magma i.e. rhyolite Intermediate magma i.e. andersite Mafic magma i.e. Basalt Ultramafic magma i.e. Komatiite Least viscous
Both andesite and basalt are volcanic rocks. Basalt is denser and generally darker than andesite. It has a lower silica content and more iron and magnesium. It most often forms from pahoehoe or a'a lava flows and occasionally scoria cinders. Andesite forms from more slica-rich material and is often found in the form of ash, pumice, or volcanic bombs. It may also sometimes form block lava flows, which are more viscous that a'a or pahoehoe.
The most common types of igneous rocks are andesite, basalt, diorite, gabbro, granite, pegmatite, peridotite, porphyry, pumice, rhyolite, syenite, and trap.Igenous rocks are rocks that melt and become molten lava, then harden.
Lava flows cool to form extrusive igneous rock. Most lava flows consist of basaltic lava, cooling to form a dark rock called basalt. Some, however, may consist of andesite or, rarely, rhyolite and similar lavas.
The rock falls into the category of extrusive igneous rock. The specific type of rock depends on the type of lava. Basalt is the most common type, and is itself divided into a'a and pahoehoe. Other rocks that can form from lava include obsidian, andesite, trachyte, dacite, rhyolite, and phonolite.
When a volcano erupts explosively it does not produce lava; it produces ash and pumice. The magma involved in an explosive eruption is usually felsic or intermediate. Rhyolite, dacite, and andesite are the most commonly discussed in beginner-level geology classes. However, if water gets into the volcano any type of magma can produce an explosive eruption.