Igneous Rock With Name On Picture Obsidan Pumice And Granite

We know igneous rocks have two basic types.

Igneous rock with name on picture obsidan pumice and granite.

Pictures and brief descriptions of some common igneous rock types are shown on this page. Eventually the overlying rocks are removed exposing the granite. Granite is an intrusive igneous rock. Igneous rocks from left to right.

The table below shows examples of common metamorphic rocks. Another name for scoria is volcanic cinders and the landscaping product commonly called lava rock is scoria as is the cinder mix widely used on running tracks. Gabbro andesite pegmatite basalt pumice porphyry obsidian granite and tuff. Granite coarse or medium grained intrusive igneous rock that is rich in quartz and feldspar.

Discriptions are adapted from the usgs. Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a mineraloid the result is a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture see photo. Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window.

Scoria like pumice is a lightweight extrusive rock. When molten lava magma is cooling slowly below the surface of the earth and forms large crystals in the rocks they known as intrusive igneous rocks. Obsidian has a glassy lustre and is slightly harder than window glass. Obsidian is extremely rich in silica about 65 to 80 percent is low in water and has a chemical composition similar to rhyolite.

Magma that has reached the surface is lava. Granite is the most widespread of igneous rocks underlying much of the continental crust. Molten rock material below the surface is called magma. Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock.

All pictures of igneous rocks are courtesy of the usgs united states geological survey with the exception of granite. Some cool so quickly that they form an amorphous glass. Learn more about the properties and uses of granite in this article. Obsidian igneous rock occurring as a natural glass formed by the rapid cooling of viscous lava from volcanoes.

It is the most common plutonic rock of the earth s crust forming by the cooling of magma silicate melt at depth. Extrusive igneous rocks erupt onto the surface where they cool quickly to form small crystals. This type of igneous rock has large distinct gas bubbles and a darker color. Igneous rocks that solidified within the crust are plutonic or intrusive rocks.

These rocks include andesite basalt dacite obsidian pumice rhyolite scoria and tuff.