Intrusive and Extrusive
Igneous rocks are called fire rocks because it is formed by magma. Igneous rocks can be formed in two ways, and they are intrusive and extrusive. Intrusive rocks are formed when magma cools down inside the earth. Extrusive rocks are formed when magma comes out of a volcano and flows down to the surface. When magma cools down underground it's processed and is much slower than when it cools down on the surface.
Igneous Rocks Found in Georgia
Obsidian
Obsidian rock is found when molten rock cools down very fast. It is used in cutting sharp edges. Obsidian has a black color and is very smooth. It is volcanic glass after it cools down.
Obsidian rock is found when molten rock cools down very fast. It is used in cutting sharp edges. Obsidian has a black color and is very smooth. It is volcanic glass after it cools down.
Pumice
Pumice is a powder form of pumicite. It forms with volcanic gases. Pumice is used in lightweight concrete, and cinder blocks. It mostly has cream color. Pumice is 6 on the hardness scale.
Pumice is a powder form of pumicite. It forms with volcanic gases. Pumice is used in lightweight concrete, and cinder blocks. It mostly has cream color. Pumice is 6 on the hardness scale.
Info: http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/intrus.html
http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/intrus.html#c2
http://www.fi.edu/fellows/fellow1/oct98/create/igneous.htm
http://en.wikipedia.org/wiki/Obsidian
http://geology.com/rocks/obsidian.shtml
http://en.wikipedia.org/wiki/Pumice
http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/intrus.html#c2
http://www.fi.edu/fellows/fellow1/oct98/create/igneous.htm
http://en.wikipedia.org/wiki/Obsidian
http://geology.com/rocks/obsidian.shtml
http://en.wikipedia.org/wiki/Pumice