Hydroxylapatite (Ca5(PO4)3(OH))—a compound with calcium, phosphate, and hydroxide ions—is the mineral portion of human and animal bones and teeth.
Mineral-like substances that do not strictly meet this definition are sometimes classified as mineraloids.
Another occurrence is as secondary oxidation products of original sulfide minerals.
The halide class includes the fluoride, chloride, and iodide minerals.
Chemistry and crystal structure (and crystal habit) together define a mineral.
Minerals that are closely related in composition and structure are grouped together.
Many minerals are the raw materials from which metals are extracted; others are used as gemstones.
A mineral may show good crystal habit or form, or it may be massive, granular, or compact with only microscopically visible crystals.
Over half the known mineral species are so rare that they have been found in only a handful of samples, and many are known from only one or two small grains.
Similarly, some minerals have different chemical compositions but the same crystal structure.
Sulfates also occur in hydrothermal vein systems as gangue minerals, along with sulfide ore minerals.
The carbonate minerals consist of those that contain the anion CO32-.
Unfortunately, human history is also marked by examples of people who have stolen, plundered, and fought over valuable minerals.
The halides are a group of minerals that form salts such as fluorite (calcium fluoride), halite (sodium chloride), sylvite (potassium chloride), and sal ammoniac (ammonium chloride).
The largest group of minerals by far are the silicates (most rocks are more than 95 percent silicates).
The typical, outward appearance of a mineral is called the "crystal habit."
Crystal structure greatly influences a mineral's physical properties.
An inexperienced observer may be misled by a mineral's crystal habit, as the crystal system can be hidden or disguised.
The sulfate class also includes the chromate, molybdate, selenate, sulfite, tellurate, and tungstate minerals.
When two or more minerals have the same chemical composition but differ in crystal structure, they are known as polymorphs.
A mineral is defined as a naturally occurring, inorganic solid with a definite chemical composition and crystalline structure.
Minerals are extremely valuable for a wide variety of uses.
The crystal structure of a mineral is the orderly, geometric arrangement of atoms or ions in the mineral's internal structure.
Minerals in this group include gold, silver, copper, antimony, bismuth, graphite, and sulfur.
Other rocks contain many minerals, and the specific minerals in a rock can vary widely.
Minerals are inorganic crystalline compounds formed by natural processes.
Some crystal habits are distinctive of certain minerals, but in most cases, a mineral exhibits a variety of habits that are influenced by the growth conditions of the crystals.
A rock is an aggregate of two or more minerals, and it may also include organic remains.
The list below, which follows the Dana classification system, is in approximate order of abundance of the minerals in the Earth's crust.
Most minerals are formed through geochemical processes, but some (carbonates and phosphates) are produced by biological systems.
The quartz, mica, and feldspar groups of minerals are common, while others have been found in only one or two locations worldwide.
When identifying and classifying a mineral, the following physical properties are taken into consideration.
The classification of minerals is also based on their chemical composition.
The carbonate class includes the nitrate and borate minerals.
The latter subgroup consists of a continuous series of minerals, from sodium-rich albite (NaAlSi3O8) to calcium-rich anorthite (CaAl2Si2O8), with four recognized intermediate compositions.
The phosphate mineral group includes any mineral in which the anion takes the tetrahedral form AO4-n, where A can be phosphorus, antimony, arsenic or vanadium.
Iron in diet. Iron is a mineral found in every cell of the body. Iron is considered an essential mineral because it is needed to make hemoglobin, a part of blood cells.Jan 7, 2017
There are ten minerals in Mohs scale, talc, gypsum, calcite, fluorite, apatite quartz, topaz, corundum, and for last and hardest, diamond. Because the Mohs scale was made long ago, it is not exactly correct - for example, several minerals are now known to be harder than the diamond.
The simple explanation for the Red Planet's color is that its regolith, or surface material, contains lots of iron oxide — the same compound that gives blood and rust their hue. But why does Mars have so much iron, why is that iron "oxidized," and why does iron oxide look red?Aug 8, 2012