Vaterite is a mineral, a
polymorph of
calcium carbonate (
Ca C O3). It was named after the German mineralogist
Heinrich Vater. It is also known as mu-
calcium carbonate (μ-CaCO
3). Vaterite belongs to the
hexagonal crystal system
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crysta ...
, whereas calcite is
trigonal
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal ...
and aragonite is
orthorhombic
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with ...
.
Vaterite, like
aragonite
Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including pre ...
, is a
metastable phase of calcium carbonate at ambient conditions at the surface of the earth. As it is less stable than either calcite or aragonite, vaterite has a higher
solubility
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubi ...
than either of these phases. Therefore, once vaterite is exposed to
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
, it converts to
calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratc ...
(at low temperature) or
aragonite
Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including pre ...
(at high temperature: ~60 °C). At 37 °C for example a solution-mediated transition from vaterite to calcite occurs, where the vaterite dissolves and subsequently precipitates as calcite assisted by an
Ostwald ripening
Ostwald ripening is a phenomenon observed in solid solutions or liquid sols that describes the change of an inhomogeneous structure over time, i.e., small crystals or sol particles dissolve, and redeposit onto larger crystals or sol particles ...
process.
However, vaterite does occur naturally in
mineral spring
Mineral springs are naturally occurring springs that produces hard water, water that contains dissolved minerals. Salts, sulfur compounds, and gases are among the substances that can be dissolved in the spring water during its passage un ...
s, organic tissue,
gallstone
A gallstone is a stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to the presence of mi ...
s,
urinary calculi and plants. In those circumstances, some impurities (
metal
A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...
ions or organic matter) may stabilize the vaterite and prevent its transformation into calcite or aragonite. Vaterite is usually colorless.
Vaterite can be produced as the first mineral deposits repairing natural or experimentally-induced shell damage in some aragonite-shelled mollusks (e.g. gastropods). Subsequent shell deposition occurs as aragonite. In 2018, vaterite was identified as a constituent of a deposit formed on the leaves of ''
Saxifraga'' at
Cambridge University Botanic Garden
The Cambridge University Botanic Garden is a botanical garden located in Cambridge, England, associated with the university Department of Plant Sciences (formerly Botany School). It lies between Trumpington Road to the west, Bateman Street to ...
.
Vaterite has a
JCPDS number of .
See also
*
Monohydrocalcite, CaCO3·H2O
*
Ikaite, CaCO3·6H2O
*
List of minerals
This is a list of minerals for which there are articles on Wikipedia.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a m ...
*
List of minerals named after people
This is a list of minerals named after people. The chemical composition follows name.
A
* Abelsonite: C31H32N4Ni – American physicist Philip Hauge Abelson (1913–2004)alfred
*Abswurmbachite: Cu2+Mn3+6O8SiO4 – German mineralogist I ...
References
Calcium minerals
Carbonate minerals
Hexagonal minerals
Minerals in space group 194
Polymorphism (materials science)
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