Examples of Common Igneous RocksAndesite is a gray to black volcanic rock. It is generally erupted from stratovolcanoes as thick lava flows. It can also generate strong explosive eruptions to form pyroclastic flows.- Basalt is a hard, black volcanic rock.
Wreckage of the mad experiment. Less than ½ of the weight of basalt is silica (SiO2). Because of basalt's low silica content, it has a low viscosity (resistance to flow). This enables basaltic lava to flow quickly and allows volcanic gases to escape without explosive events.Dacite lava is most often light gray, but can be dark gray to black.
It is one of the most common rock types associated with enormous Plinian-style eruptions.is light and porous. It forms during explosive eruptions. Pumice is full of holes caused by expanding volcanic gases. It is composed of volcanic glass and minerals, and can form in all types of magma: basalt, andesite, dacite, and rhyolite.is usually black in color though it can also be red or have a greenish tint.
It is a dense volcanic glass, usually composed of rhyolite, rich in iron and magnesium.Obsidian is formed when the lava cools so quickly that crystals do not have time to grow. Obsidian fractures with very sharp edges. It was used by Stone Age cultures for making knives, arrowheads, and other tools where sharp edges are important.is a light-colored volcanic rock. It has a high silica content which makes it very viscous.
This prevents gases from escaping causing rhyolite eruptions to be explosive.is a common intrusive plutonic igneous rock. Because it cools slowly crystals have time to form. The name granite comes from the Latin word granum which means “a grain” for the coarse grain crystalline structure of the rock.All pictures of igneous rocks are courtesy of the USGS - United States Geological Survey with the exception of granite.
Discriptions are adapted from the USGS.The table below shows examples of common metamorphic rocks.Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window. Examples of Common Metamorphic Rocksis a coarse-grained metamorphic rock derived from sandstone.is a metamorphic rock that comes from metamorphosed limestone or dolomite.is a fined grained metamorphic rock.is a fined grained metamorphic rock.is a course grained metamorphic rock.is a medium to course grained metamorphic rock.The table below shows examples of common clastic sedimentary rocks. They are listed by grain size in decending order. Grain size is one factor in.Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window. Examples of Clastic Sedimentary Rocksis made up of rounded pebbles cemented together.is made up of angular pebbles cemented together.is calcium carbonate deposited by the shells of once living creatures or from the residue of water.is sand grains cemented together into solid stone.is made from silt particles cemented together.is made from silt particles cemented together. It is similar to siltstone but with even finer grain size,Igneous metamorphic sedimentary rock are the three main types of rock on earth.Read more about Igneous Metamorphic Sedimentary Rock.
All three rock types - igneous, sedimentary, and metamorphic - make up a portion of the rock cycle. Igneous rocks are rocks that formed directly from magma and can form either in the earth or on.