Taken from the following website: http://skywalker.cochise.edu/wellerr/GLG101/GLG101-igneous-rocks.htm
“Pegmatite is very coarsely crystallized. Some of the
largest crystals in the world have
been found in pegmatites. Pegmatites
often have the same mineral composition of granites with large crystals of mica and
feldspar. Gem minerals, such as tourmaline and beryl are found in
pegmatites.”
Pic: Shkatulka pegmatite
Geographic Area of Abundance: Russia
METAMORPHIC
“Marble is a metamorphic
rock that comes from metamorphosed limestone or dolomite. Limestone is mostly
calcite or calcium carbonate, CaCO3. Dolomite CaMg(CO3)2 is related to
limestone but is rich in magnesium. Marble has a uniform texture
(non-foliated).”
Pic: Gray Marble
Geographic Area of Abundance: China, Italy, United States, India and Greece, among others
SEDIMENTARY
Taken from the following website: http://geology.com/rocks/breccia.shtml
“Breccia
is a term most often
used for clastic sedimentary rocks that are composed of large
angular fragments (over two millimeters in diameter). The spaces between the
large angular fragments can be filled with a matrix of smaller particles or a
mineral cement that binds the rock together.“
Pic: Chert Breccia
Geographic Area of Abundance: Western Australia
SOIL TEXTURE DIAGRAM
No comments:
Post a Comment