Tobermorite
Encyclopedia
Not to be confused with torbernite
Torbernite
The chemical formula of torbenite is similar to that of autunite in which a Cu2+ cation replaces a Ca2+. The number of water hydration molecules can vary between 12 and 8, giving rise to the variety of metatorbernite when torbernite spontaneously dehydrates...

, a hydrated copper uranyl phosphate.


Tobermorite is a calcium silicate hydrate
Calcium silicate hydrate
Calcium Silicate Hydrate is the main product of the hydration of Portland cement and is primarily responsible for the strength in cement based materials.-Preparation:...

 mineral with chemical formula:
Ca5Si6O16(OH)2·4H2O

or
Ca5Si6(O,OH)18·5H2O


Two structural varieties are distinguished: tobermorite-11 Å and tobermorite-14 Å.
Tobermorite occurs in hydrated cement
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

 paste and can be found in nature as alteration mineral in metamorphosed
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...

 limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 (e.g. in the Maqarin Area (North Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

), or in Crestmore (Riverside County, California, USA)) and in skarn
Skarn
Skarn is an old Swedish mining term originally used to describe a type of silicate gangue, or waste rock, associated with iron-ore bearing sulfide deposits apparently replacing Archean age limestones in Sweden's Persberg mining district. In modern usage the term "skarn" has been expanded to refer...

.

Tobermorite was first described in 1880 for an occurrence in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, on the Isle of Mull
Isle of Mull
The Isle of Mull or simply Mull is the second largest island of the Inner Hebrides, off the west coast of Scotland in the council area of Argyll and Bute....

, around the locality of Tobermory.

See also

  • Other Calcium silicate hydrate
    Calcium silicate hydrate
    Calcium Silicate Hydrate is the main product of the hydration of Portland cement and is primarily responsible for the strength in cement based materials.-Preparation:...

     minerals:
    • Afwillite
      Afwillite
      Afwillite is a calcium hydroxide nesosilicate mineral with formula Ca32.2H2O. It occurs as glassy, colorless to white prismatic monoclinic crystals. Its Mohs scale hardness is between 3 and 4...

    • Clinotobermorite
    • Jennite
      Jennite
      Jennite is a calcium silicate hydrate of general chemical formula: Ca9Si6O186·8.Jennite occurs in hydrated cement paste and can be found in nature in particular conditions, e.g., as alteration mineral in metamorphosed limestone and skarn....

    • Plombierite
    • Thaumasite
      Thaumasite
      -External links:*...

  • Other Calcium aluminium silicate hydrate minerals:
    • Hydrogarnet
    • Hydrotalcite
      Hydrotalcite
      Hydrotalcite is a layered double hydroxide of general formula Hydrotalcite is a layered double hydroxide of general formula Hydrotalcite is a layered double hydroxide of general formula (Mg6Al2(CO3)(OH)16·4(H2O) whose name is derived from its resemblance with talc and its high water content. It is...


External links

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