Serpentinite is a rock composed of one or more serpentine minerals. Chrysotile or white asbestos is the most commonly encountered form of Asbestos, accounting for approximately 95% of the asbestos in place in the United States In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere The serpentine group describes a group of common rock-forming hydrous Magnesium Iron phyllosilicate (()3 Minerals they A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Minerals in this group are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change Ultramafic (also referred to as ultrabasic) rocks are igneous and meta -igneous rocks with very low Silica content (less than 45% generally The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided The alteration is particularly important at the sea floor at tectonic plate boundaries. Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere It is the state rock of California, USA. California ( is a US state on the West Coast of the United States, along the Pacific Ocean. The United States of America —commonly referred to as the

Contents 1 Formation 2 Serpentinite reactions 3 Carbon sequestration 4 Bleistein or Ofenstein 5 See also 6 External links 7 References

Formation

Serpentinization is a geological low-temperature and metamorphic process involving heat and water in which low-silica mafic and ultramafic rocks are oxidized and hydrolyzed with water into serpentinite. Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Mafic is an adjective describing a Silicate mineral or rock that is rich in magnesium and iron the term was derived by contracting "magnesium" and "ferric" Ultramafic (also referred to as ultrabasic) rocks are igneous and meta -igneous rocks with very low Silica content (less than 45% generally Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions Peridotite, including dunite, at and near the seafloor and in mountain belts is converted to serpentine, brucite, magnetite, and other minerals -- some rare, such as awaruite (Ni₃Fe), and even native iron. A peridotite is a dense coarse-grained Igneous rock, consisting mostly of the minerals Olivine and Pyroxene. Dunite (ˈduːnaɪt or /ˈdʌnaɪt/ is an igneous, Plutonic rock, of Ultramafic composition with coarse-grained or Phaneritic The serpentine group describes a group of common rock-forming hydrous Magnesium Iron phyllosilicate (()3 Minerals they Brucite is the Mineral form of Magnesium hydroxide, with the chemical formula Mg ( OH)2 Magnetite is not to be confused with Magnesite or Maghemite. Magnetite is a ferrimagnetic Mineral with chemical Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 In the process large amounts of water are absorbed into the rock increasing the volume and destroying the structure.

The density changes from 3. 3 to 2. 7 g/cm³ with a concurrent volume increase of about 40%. The reaction is exothermic and large amounts of heat energy are produced in the process.

Rock temperatures can be raised by about 260 ^oC, providing an energy source for formation of non-volcanic hydrothermal vents. A hydrothermal vent is a Fissure in a planet's surface from which geothermally heated Water issues The magnetite-forming chemical reactions produce hydrogen gas. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Sulfates and carbonates are reduced and form methane and hydrogen sulfide. In Chemistry, a carbonate is a salt or Ester of Carbonic acid. Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Hydrogen sulfide (or hydrogen sulphide) is the Chemical compound with the formula H 2 S. The hydrogen, methane, and hydrogen sulfide provide energy sources for deep sea chemotroph microorganisms. Chemotrophs are organisms that obtain Energy by the Oxidation of Electron donating Molecules in their environments A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually

Serpentinite reactions

Serpentinite is formed from olivine via several reactions, some of which are complementary. The Mineral olivine (when gem-quality also called Peridot) is a Magnesium Iron silicate with the formula ( Mg Olivine is a solid solution between the magnesium-endmember forsterite and the iron-endmember fayalite. A solid solution is a Solid - state Solution of one or more solutes in a Solvent. Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Forsterite (Mg2SiO4 is the magnesium rich end-member of the Olivine Solid solution series Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Fayalite (Fe2SiO4 is the Iron rich end-member of the Olivine solid-solution series Serpentinite reactions 1a and 1b, below, exchange silica between forsterite and fayalite to form serpentine-group minerals and magnetite. These are highly exothermic reactions.

Reaction 1a:
Fayalite + water → Magnetite + aqueous silica + hydrogen

Reaction 1b:
Forsterite + aqueous silica → Serpentine

Other possibilities include the reaction of olivine plus water to yield serpentine plus Mg(OH)₂ (brucite), and reactions in which magnesium and silica are transported out of the serpentinizing volume. Brucite is the Mineral form of Magnesium hydroxide, with the chemical formula Mg ( OH)2

A similar suite of reactions involves pyroxene-group minerals, though less readily and with complication of the additional end-products due to the wider compositions of pyroxene and pyroxene-olivine mixes. The pyroxenes are a group of important rock-forming Silicate minerals found in many Igneous and metamorphic rocks. Talc and magnesian chlorite are possible products, together with the serpentine minerals antigorite, lizardite, and chrysotile. Talc (derived from the Persian via Arabic talq) is a Mineral composed of Hydrated Magnesium Silicate with This discusses some chlorine compounds Chlorite is also a type of mineral see Chlorite group. The serpentine group describes a group of common rock-forming hydrous Magnesium Iron phyllosilicate (()3 Minerals they The serpentine group describes a group of common rock-forming hydrous Magnesium Iron phyllosilicate (()3 Minerals they Chrysotile or white asbestos is the most commonly encountered form of Asbestos, accounting for approximately 95% of the asbestos in place in the United States The final mineralogy depends both on rock and fluid compositions, temperature, and pressure. Antigorite forms in reactions at temperatures that can exceeed 600°C during metamorphism, and it is the serpentine-group mineral stable at the highest temperatures. The serpentine group describes a group of common rock-forming hydrous Magnesium Iron phyllosilicate (()3 Minerals they Lizardite and chrysotile can form at low temperatures very near the Earth's surface. Fluids involved in serpentinite formation commonly are highly reactive and may transport calcium and other elements into surrounding rocks; fluid reaction with these rocks may create metasomatic reaction zones enriched in calcium and called rodingites. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Metasomatism is the chemical alteration of a rock by Hydrothermal and other fluids

In the presence of carbon dioxide, however, serpentinitization may form either magnesite (MgCO₃) or generate methane (CH₄). It is thought that some hydrocarbon gases may be produced by serpentinite reactions within the oceanic crust, and the serpentinite reaction is a key argument for the theory of abiogenic petroleum origin. The hypothesis of abiogenic petroleum origin is an alternative hypothesis to the biological origin theory which was popular in Russia and Ukraine between

Reaction 2a:

Olivine + Water + Carbonic acid → Serpentine + Magnetite + Methane

or, in balanced form: 18Mg₂SiO₄ + 6Fe₂SiO₄ + 26H₂O + CO₂ → 12Mg₃Si₂O₅(OH)₄ + 4Fe₃O₄ + CH₄

Reaction 2b:

Olivine + Water + Carbonic acid → Serpentine + Magnetite + Magnesite + Silica

Reaction 2a is favored if the serpentinite is Mg-poor or if there isn't enough carbon dioxide to promote talc formation. Talc (derived from the Persian via Arabic talq) is a Mineral composed of Hydrated Magnesium Silicate with Reaction 2b is favored in highly magnesian compositions and low partial pressure of carbon dioxide. (Something is missing from Reaction 2b because Fe is oxidized and nothing gets reduced. )

The degree to which a mass of ultramafic rock undergoes serpentinisation depends on the starting rock composition and on whether or not fluids transport calcium, magnesium and other elements away during the process. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 If an olivine composition contains sufficient fayalite, then olivine plus water can completely metamorphose to serpentine and magnetite in a closed system. In most ultramafic rocks formed in the Earth's mantle, however, the olivine is about 90% forsterite endmember, and for that olivine to react completely to serpentine, magnesium must be transported out of the reacting volume. The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided

Serpentinitization of a mass of peridotite usually destroys all previous textural evidence because the serpentine minerals are weak and behave in a very ductile fashion. However, some masses of serpentinite are less severely deformed, as evidenced by the apparent preservation of textures inherited from the peridotite, and the serpentinites may have behaved in a rigid fashion. Rock microstructure includes the texture of a rock and the small scale rock structures

Carbon sequestration

Serpentinite has been proposed as an efficient reagent for carbon sequestration using the magnesite reaction, above, or a variation where serpentine is reacted with carbon dioxde and hydrogen to form magnesite, magnetite, silica. The ideal composition of olivine or serpentinite for this process is thus highly magnesian, to favor production of magnesite and the fixation of carbon.

Bleistein or Ofenstein

A lamelled variety of serpentinite is found in South Tyrol and is locally called Bleistein (Leadstone) or Ofenstein (Ovenstone). It was used primarily for building wood burning indoor heating stoves as it has the capacity of storing and dispersing heat very well along the veins. A New York educational documentary film production company [1] is releasing a film that describes the quarrying of this stone and its use in the construction of stoves.

See also

• Lost City (hydrothermal field)
• Olivine
• Hydrothermal and metasomatism
• Metamorphism
• Nephrite
• Carbon sequestration
• Talc carbonate
• Soapstone
• Life on Mars

External links

• ZECA Corporation serpentinite carbon sequestration process

References

• Serpentinization: The Heat Engine at Lost City and Sponge of the Oceanic Crust
• H2-rich fluids from serpentinization: Geochemical and biotic implications

Lost City is a field of Hydrothermal vents in the mid-Atlantic ocean that differ significantly from the Black smoker vents found in the late 1970s The Mineral olivine (when gem-quality also called Peridot) is a Magnesium Iron silicate with the formula ( Mg Hydrothermal circulation in its most general sense is the circulation of hot water 'hydros' in the Greek meaning water and 'thermos' meaning heat Metasomatism is the chemical alteration of a rock by Hydrothermal and other fluids Metamorphism can be defined as the solid state recrystallisation of pre-existing rocks due to changes in heat and/or pressure and/or introduction of fluids i Nephrite is a variety of the calcium and magnesium rich Amphibole mineral Actinolite (aggregates of which also make up one form of Asbestos) Talc carbonate is a geologic term for a suite of rock and mineral compositions found in metamorphic Ultramafic rocks Soapstone (also known as steatite or soaprock) is a Metamorphic rock, a talc- Schist. Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth.

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