Sedimentary limestone can reform into igneous and metamorphic rock types.
Rocks and minerals are similar in size and shape and can easily be mistaken for one another by a layman's eye. They differ scientifically, however, in their formation, chemical composition, classification and special properties. Rocks are unique composite substances that form in tandem with an array of different minerals, whereas minerals have a homogenous, well-defined composition. The three basic rock types -- igneous, sedimentary and metamorphic -- generally contain a characteristic composite of minerals by general location, which can help to classify the rocks with certainty. Minerals generally form inside established rocks in type-specific crystal colonies, helping to identify them as well.
Formation
The processes by which rocks and minerals form are different. Minerals form by crystallization and remain true to their nature. Rocks are constantly transforming into other rock types.
For minerals to crystallize, the initial structure of atoms must remain organized despite aggressive exposure to geologic processes. Minerals form in moisture-rich cavities in various types of rocks and grow according to 14 basic crystalline patterns.
Rocks are subjected to a cyclical process during formation. A compound can begin as igneous rock, formed after magma cools, and then be transformed into sedimentary rock when compaction and cementation is present. A sedimentary rock can be transformed into a metamorphic rock with heat and pressure.
Chemical Composition
The chemical composition of minerals and rocks also differ. Few chemical elements are involved in the formation of minerals. This small group of common elements, which are found in abundance close to the Earth's crust, include oxygen, silica and iron. Rocks are generally comprised of many more chemical constituents than minerals because they are exposed to numerous elements that are only found deep within the Earth.
Classification
In most cases, minerals are classified by type in a laboratory by tediously viewing their crystalline lattice network under a microscope. For easier identification, minerals are also classified on a hardness scale. Minerals such as talc and gypsum are very soft; topaz and diamond are extremely hard. In contrast, rocks can usually be classified by a layperson with the naked eye. Sometimes, however, chemical and other specific laboratory tests are done on rocks to classify them further.
Special Properties
Chemical tests can show special properties that are specific to both rocks and minerals. Certain types of calcite exhibit an effervescent characteristic when exposed to hydrochloric acid, for example. Magnetism, another property tested in labs, is a special property found in minerals as well as rocks. These types of special properties help researchers to define the chemical constituents of both rocks and minerals even further.
Related posts
Water and conglomerate rocks go hand in hand.Wherever pebbles and water are found, conglomerate rocks are rarely far behind. Though they form a relatively small portion of the total sedimentary ro...
Salt Flats at Death Valley, CaliforniaThe Surface of the EarthChemical sedimentary rocks form at the earth's surface. Sedimentary rocks are rocks that have been placed by weathering or erosion in...
American Indian stone artifacts are often made of chert.Chert is one the major sedimentary rock types; it occurs as a common surface rock and is a major component of gravel beds and bars in rivers...
How Do Organic Sedimentary Rocks Form?The Basics of the Rock CycleThere are three different types of rocks that make up the Earth: metamorphic, igneous and sedimentary. As the Earth renews its cru...
In the Grand Canyon, you can see sedimentary rocks that have been deposited over millions of years.Metamorphic and sedimentary rocks are two of the three classifications of rocks found on the eart...
