Larnite is a

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

silicate mineral Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually consid ...

with formula: Ca₂SiO₄. It is the calcium member of the olivine group of minerals. It was first described from an occurrence at

Scawt Hill Scawt Hill is a volcanic plug in County Antrim, Northern Ireland, in the borough of Larne, 5 km from the village of Ballygally. It gets its name from the Ulster Scots "" meaning scaly, scabby or rugged. Alternatively, '' 'scawt' '' mea ...

Larne Larne (, , the name of a Gaelic territory) is a town on the east coast of County Antrim, Northern Ireland, with a population of 18,755 at the 2011 Census. It is a major passenger and freight roll-on roll-off port. Larne is administered by Mid ...

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...

in 1929 by

Cecil Edgar Tilley Cecil Edgar Tilley Fellow of the Royal Society, FRS HonFRSE Geological Society, PGS (14 May 1894 – 24 January 1973) was an Australian-UK, British petrologist and geologist. Life He was born in Unley, Adelaide, the youngest child of John Thoma ...

and named for the location. At the type locality it occurs with

wollastonite Wollastonite is a calcium inosilicate mineral ( Ca Si O3) that may contain small amounts of iron, magnesium, and manganese substituting for calcium. It is usually white. It forms when impure limestone or dolomite is subjected to high temperature ...

spurrite Spurrite is a white, yellow or light blue mineral with monoclinic crystals. Its chemical formula is Ca5( Si O4)2 CO3. Spurrite is generally formed in contact metamorphism zones as mafic magmas are intruded into carbonate rocks.Smith, J.V. (19 ...

perovskite Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as (XIIA2+VIB4+X2−3), known a ...

, merwinite,

melilite Melilite refers to a mineral of the melilite group. Minerals of the group are solid solutions of several endmembers, the most important of which are gehlenite and åkermanite. A generalized formula for common melilite is ( Ca, Na)2( Al, Mg, ...

and

gehlenite Gehlenite, (Ca2Al lSiO7, is a sorosilicate, Al-rich endmember of the melilite complete solid solution series with akermanite.Deer et al., 1993 The type locality is in the Monzoni Mountains, Fassa Valley in Trentino in Italy, and is named after ...

. It occurs in contact metamorphosed

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

s and

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...

s adjacent to

basaltic Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...

intrusives.

Dicalcium silicate Calcium silicate is the chemical compound Ca2SiO4, also known as calcium orthosilicate and is sometimes formulated as 2CaO·SiO2. It is also referred to by the shortened trade name Cal-Sil or Calsil. It occurs naturally as the mineral larnite. ...

is chemically, β–Ca₂SiO₄, sometimes represented by the formula 2CaO·SiO₂. When used in the cement industry, the mineral is usually referred to as belite.

References

* Nesosilicates Monoclinic minerals Minerals in space group 14 {{silicate-mineral-stub