other names: Calcite, calcite
mineral class: Carbonates and nitrates
chemical formula: CaCO3
Chemical elements: Calcium, carbon, oxygen
Similar minerals: Aragonite, dolomite
colour: colorless, white
shine: Glass gloss
crystal structure: trigonal
mass density: 2,7
magnetism: not magnetic
Mohs hardness: 3
stroke color: White
transparency: transparent to opaque
use: Building material, gem stone
General information about calcite:
calcite or calcite describes a mineral that is widely distributed on Earth and is considered a group of carbonates, consisting mainly of calcium and other minerals, oxygen and carbon. The name derives from the Greek word "chal" and the Latin term "calx", both of which translate to "lime". Calcite is the basis of many types of rocks, including limestone and marble. This calcium carbonate forms trigonal crystals, grains or fibers and appears both transparent and opaque. Rocks that form delicate and flaky crystals are called paper-spar or leaf-spar. Calcite in its pure form is colorless or pure white with a matte surface, but may also appear in different colors depending on the chemical composition and location. The orange-calcite is the most common variety, by admixtures of cobalt, lead, magnesium, iron or zinc but also pink, yellow, blue, greenish, violet, red and white milky forms are widespread. Under the influence of UV light calcite can phosphoresce or fluoresce. All varieties have a shell-like or brittle fracture in common, while colored varieties show a striking mother-of-pearl or glass luster.
Occurrence and localities:
Calcite is one of the most widespread minerals in the world and can form on the earth's surface, on the seabed and in cave systems as well as in the body of humans and animals such as calcification on the teeth (tartar and plaque). As a sedimentary mineral calcite develops when calcareous water evaporates over millions of years. Often calcite is associated with other minerals such as galena, quartz or pyrite. Many land and aquatic molluscs make their housing from calcite. The stalactites and stalagmites typical of stalactite caves are formed as Al-deposits of calcite dissolved in acidic water. The largest crystals are formed by the deposition of dead marine animals such as corals, shells and shellfish on the seabed. Calcite occurs on all continents and on all seabeds. The main countries where calcite is promoted on a large scale include Brazil, Mexico, the United States and South Africa. In Europe, especially Germany, Iceland, Italy and France are significant for the extraction of calcite.
The use of this mineral is extremely diverse, due to the use of different calcite rock types such as marble and limestone. As a basis of such rocks calcite is used as a valuable and sought-after building material. Calcite is also used for the production of artificial fertilizer, as an additive for various paints and varnishes, glass and cement, and as a base for calcareous terrarium sand, which is well tolerated by domestic digestibility. Although calcite is actually a relatively soft mineral that is very sensitive to external influences, it is also used in jewelery making. In particular, the bright sun-yellow orange calcite, which was already worshiped by the Indians of Mexico as a burning, protecting from evil spirits stone, is often processed into pendants and beads for necklaces and bracelets.