The most valuable rocks are ores. These rocks contain minerals or metals that can be of great commercial value, such as gold, platinum, copper, iron, nickel or silver.Know More
Some elements are found in more than one type of rock, and some rocks contain more than one type of element. Galena, for example, is a major source of lead, but it can also contain silver.
Nickel, a silvery white, shiny metal that has leant its name to an American coin, is found in limonite, which also contains iron. Another nickel ore is pentlandite, which contains iron as well as small amounts of cobalt.
Iron, which is strong, ductile and malleable, is one of the most sought after metals and is inexpensive because it's abundant. This is true even though iron is such a reactive element that it's rarely found in its free state. Among the ores of iron besides those mentioned are hematite, goethite and magnetite. The Earth's core is made of iron, and it's even found in meteors in the form of siderite.
Copper is also found in many types of rocks, especially rocks that are abundant in carbonates, oxides and sulphides. These ores include rocks that have their own esthetic value such as malachite, cuprite and azurite.Learn more about Geology
Metamorphic rocks are formed when the properties of existing igneous or sedimentary rocks are altered by contact with heat or pressure. They are typically found deep underground where the conditions necessary for their formation exist.Full Answer >
Rocks and minerals are inorganic compounds and occur throughout the world but have distinct physical characteristics, distinguishing features and societal uses that set them apart. Minerals are generally lighter in weight and color than rocks and hold value for their aesthetic properties. Rocks, in contrast, are denser, darker and hardier and find use in the industrial and construction industries.Full Answer >
Rocks are different from minerals in that minerals are single crystalline accumulations of one or more elements, while rocks are solid accumulations of one or more minerals. Rock can either refer to a particular, detached object or, in a general sense, as a synonym for stone, generally referring to a portion of the substance. Individual minerals can be obvious in rocks, as with granite, or microscopic, as with many basalts.Full Answer >
Rocks are formed in three primary ways, and each method produces rocks with different characteristics. Rocks are either classified as sedimentary, igneous or metamorphic, depending on the manner in which they were formed. Most rocks encountered in everyday life are sedimentary, although some igneous rocks, such as granite, are also common.Full Answer >