Magnesium Sulphate: The chemical composition is MgSiO 4 which is white crystalline. Get your content registered in a globally recognized 3rd party system. Its striking iridescence gives it the nickname peacock copper or peacock ore.. Mineralogy. This dynamic crystal also carries deeply healing and purifying vibrations. Alloy Guide. 1. Physical properties. Although its usually white in color, it also comes in different colors, like grey, brown, yellow, and even pink, depending on which minerals were various widely in chemical composition with CrO3. The reaction produces magnesium and water. Hematite (/ h i m t a t, h m -/), also spelled as haematite, is a common iron oxide compound with the formula, Fe 2 O 3 and is widely found in rocks and soils. National Without magnesium photosynthesis could not take place, and life as we know it would not exist. It depends on various factors including the chemical composition and degree of deformation of the metal. Learn more about AISI AZ91 Magnesium including its Chemical Compsition. Mineral Menu Andalusite Anhydrite Apatite Arsenopyrite Augite Azurite Barite Magnesite is a carbonate mineral used for chemicals, fire bricks, magnesium metal and more. These magnesites are often cryptocrystalline and contain silica in the form of opal or chert . Magnesite is also present within the regolith above ultramafic rocks as a secondary carbonate within soil and subsoil, where it is deposited as a consequence of dissolution of magnesium-bearing minerals by carbon dioxide in groundwaters. This article on Magnesium properties provide facts and information about the physical and chemical properties of Magnesium which are useful as homework help for chemistry students. The information in CAMEO Chemicals comes from a variety of data sources . No information available. MAGNESITE has generally low chemical reactivity. Non-flammable and non-combustible. Reacts with acids and acidic salts to generate gaseous carbon dioxide with effervescence (bubbling). Look up properties, history, uses, and more. The main raw material for making magnesite bricks is the sintered magnesia whose basic content is MgCO3. Chemical Formula: MgCO3. Halides, carbonates, sulfates, and phosphates also are relatively soft (H < 5.5).. 3. Kampala, Friday, June 30, 2022 Uganda, through Uganda National Bureau of Standards (UNBS) has been elected to the African Regional Standards Organization (ARSO) as a member of the Board. For example, the Al 2 O 3 excess, which is necessary for the formation of kyanite in the quartz-kyanite rock, is a result of depletion of alkalies and all major elements except Al, which remained unchanged. Magnesite is a member of the calcite mineral group and is often found in massive form. : Add Items Items add to dmca.com content registry. The different processes of chemical pulping include the Kraft process, which uses caustic soda and sodium sulfide and is the most common; alternatively, the use of sulfurous acid is known as the sulfite process, the neutral sulfite semichemical is treated as a third process Pulping. The beautiful Magnesite gemstone is a stone of clarity. In the presence of CO 2, E was increased to 234 kJ mole 1 but was It forms complete solid solution with siderite FeCO 3 and limited with calcite CaCO 3 and rhodochrosite The XRD results from Figure 1 also indicate that the major mineral is magnesite. Carbonate magnesium, Hydromagnesite, Magnesium carbonate, Magnesium(II) carbonate [Note: Magnesite is a naturally-occurring form of magnesium carbonate.] Fire clay composition for making fire bricks, properties, types and uses of fire bricks are explained in this article. Carbon capture and storage has a fundamental role in limiting anthropogenic warming to 1.52 C. Magnesite is a magnesium carbonate mineral with a chemical composition of MgCO 3.It is named after the presence of magnesium in its composition. Magnesium is an essential element in both plant and animal life. magnesium (Mg), chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table, and the lightest structural metal. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting Magnesite is usually white or off-white, with a glassy sheen, and yellow or brown if it contains iron. What is magnesite worth? Preparation of magnesium carbonate by reaction between magnesium salt and sodium bicarbonate. Carbon 14.25 % C 52.20 % CO 2. Delivery Time 50 Days. It has the requirement for the chemical composition and sintering degree of the sintered magnesia. A substitution of the element It can be represented by the chemical formula of FeCr 2 O 4.It is an oxide mineral belonging to the spinel group.The element magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr 2 O 4). Komatiite (/ k o m t i a t /) is a type of ultramafic mantle-derived volcanic rock defined as having crystallised from a lava of at least 18 wt% MgO. Chemical Formula: MgCO 3 Locality: Magnisa (Magnesia) Prefecture, Thessalia (Thessaly) Department, Greece Name Origin: Named after its chemical composition. Magnesite is a soft stone and carries the vibration of that softness. Download scientific diagram | Chemical composition of magnesite particles. The basic oxygen furnace (BOF) is a refractory-lined, tiltable converter into which a vertically movable, water-cooled lance is inserted to blow oxygen through nozzles at The interdependence of the chemical composition of the rock and metamorphic mineral assemblage is clearly visible. Magnesium, properties of atom, chemical and physical properties. Magnesium hydroxide (formula Mg (OH) 2) is a chemical inorganic compound, magnesium hydroxide (alkaline earth metal). a magnesium carbonate mineral with a chemical composition of MgCO3. 2. Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. Nevada variscite sometimes contains brown or black matrix that is very similar to the matrix of turquoise. If the amount of iron exceeds the magnesium, the mineral is called They are classed among the basic refractories. Variscite is an aluminum phosphate mineral with a chemical composition of AlPO 4 2H 2 O. General Magnesite Information. Carbon 14.25 % C 52.20 % CO 2. Magnesite Fire Bricks. Its main Provides comprehensive data for each element of the periodic table of elements including up to 40 properties, names in 10 languages and common chemical compounds. Different basic fire bricks available are Magnesite bricks, Magnesia-carbon, magnesia-chrome bricks etc. from publication: A Hybrid Device for Enhancing Flotation of Fine Particles by Combining Micro-Bubbles with Magnesite is a whitish mineral consisting of magnesium carbonate, used as a heat-resistant lining in some furnaces. Iron 55.85 % Fe 79.85 % Fe 2 O 3. It is the world's main source of aluminium and gallium.Bauxite consists mostly of the aluminium minerals gibbsite (Al(OH) 3), boehmite (-AlO(OH)) and diaspore (-AlO(OH)), mixed with the two iron oxides goethite (FeO(OH)) and haematite (Fe 2 O 3), the aluminium clay mineral kaolinite (Al 2 Si 2 O 5 We are a paramount organization, indulged in manufacturing and exporting premium quality Magnesite Bricks that are extensively used in front and back wall of open hearth furnaces and for glass tank checker & chemical industry. The country is the fourth largest in Europe and the second largest in the European Union, covering a total area of 505,990 km 2 with a population of 46,507,760.. Spain joined the EU in 1986, which lead to a rapid economic modernization. The decomposition temperature is above \(350\,^\circ {\rm{C}}\). Its empirical formula is Fe 3 O 4, and it is often expressed as iron (II,III) oxide. Physical properties: Magnesium nitride is a pale yellow powder. Magnesite Bricks Composition. Chemical Composition of AISI AZ91 Magnesium UNS ID: M1191x. That is because of the significant magnesium (2014b). General Magnesioferrite Information. They have a low specific gravity of They are: 1) naturally occurring, 2) inorganic, 3) solids, 4) with a definite chemical composition, and, 5) an ordered internal structure. These are igneous rocks that are composed of olivine and pyroxene (peridotite, pyroxenite).Serpentine group minerals occur less commonly in some olivine Magnesite is a mineral with the chemical formula MgCO 3 (magnesium carbonate). Magnesium chloride + sodium bicarbonate magnesium carbonate + sodium chloride + water + carbon dioxide. But when water bodies are accounted for, magnesium becomes the most abundant element on the surface of the earth. Chlorophyll is the chemical that allows plants to capture sunlight, and photosynthesis to take place. The reaction produces magnesium oxide and carbon. The decomposition of MgCO 3 (magnesite) is an interface process [734] between 813873 K and E = 150 kJ mole 1. Chemical Properties of MagnesiteHide. Asia Pacific was the largest geographic region accounting for $2.8 billion or 37.7% of the global market. MgCl2 (aq) + 2NaHCO3 (aq) MgCO3 (s) + 2NaCl(aq) + H2O(l) + CO2 (g) 2. High quality Steel Tanks Pre Packed Galvanic Magnesium Anode With Cable And Backfill Bag In Soil from China, China's leading Pre Packed Galvanic Magnesium Anode product, with strict quality control Backfill Bag Galvanic Magnesium Anode factories, producing high quality Steel Tanks Mg Anodes products. Product Description. Physical properties of magnesium hydroxide 1. Gem Encyclopedia gaseous carbon dioxide and nitrogen, and a magnesite crystal. Reacts with acids and acidic salts to generate gaseous carbon dioxide with effervescence (bubbling). Magnesite is formed when magnesium-rich China Magnesium Metal Ingot Price 99 9 Pure Silver Packing Color Square, Find details about China Magnesium Ingot, Magnesium Ingot 100g 200g 300g from Magnesium Metal Ingot Price 99 9 Pure Silver Packing Color Square - Shanxi Konno Biotech Co., Ltd. It gets its name from the fact that it contains magnesium. That is the chemical composition of the sand-lime brick. Oxygen Chemical Composition; Element Content (%) Magnesium: 60.29: Oxygen: 39.67: Physical Properties. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of Fe 2 O 3.It has the same crystal structure as corundum (Al 2 O 3) and ilmenite (FeTiO 3).With this it forms 2. the reaction of magnesium oxide with carbon: MgO + C Mg + CO (t = 2000 oC). Geology Tools. It is a white : C.RQ-121/D). Chlorophyll is a magnesium-centred porphyrin complex. Magnesium is the fourth most abundant element in the human body (Ca + > K + > Na + > Mg +) and the second most abundant cation within the bodys cells after potassium.The human body contains 760 mg of magnesium at birth and this quantity increases to 5 g at around 45 months [1,2].The total Mg 2+ body amount varies between 20 Chemical Composition of DIN AM60 Magnesium UNS ID: unknown. Serpentinite is a metamorphic rock that is mostly composed of serpentine group minerals. Magnetite is a mineral whose primary component is an iron oxide that contains equal amounts of iron (II) and iron (III). 3. Magnesium alloys are materials of interest mostly due to their high strength-to-weight ratios, exceptional machinability and low cost. Spain is a European country that borders the Mediterranean Sea, Bay of Biscay and the North Atlantic Ocean. Hydromagnesite was removed from one sample, 11AT1-J, to determine the composition of magnesite alone. However, the basic chemical composition of the material remains intact with just a few exceptions. Chemical Formula: MgCO3. Magnesium carbonate decomposes at higher temperatures to give magnesium oxide and carbon dioxide. Mohs hardness is 3.5 ~ 4.5 and specific gravity is 2.9 ~ 3.1. What is magnesite composed of? Ferrous iron commonly substitutes for some of the magnesium in dolomite, and a complete series very likely extends between dolomite and ankerite [CaFe(CO 3) 2]. In natural samples, the composition varies with respect to major and trace elements (USGS, 2001; HSE, 2005). It is a wonderful relaxing and calming stone to use in Magnesite usually forms during the alteration of magnesium-rich Learn more about DIN AM60 Magnesium including its Chemical Compsition. These are good at corrosion resistance and chemical resistance. Magnesium alloys are materials of interest mostly due to their high strength-to-weight ratios, exceptional machinability and low cost. Magnesium react with oxygen at room temperature, forming a passivating layer of MgO on the surface. Magnesite is a mineral with the chemical formula MgCO 3 (magnesium carbonate). There raw material is magnesium oxide. Magnesium 28.83 % Mg 47.80 % MgO. and the isotopic composition of the analyzed CO 2 gas needs to be corrected for this. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content. It naturally occurs in caverns and mines as nitro magnesite. 2. - Iron rich variety of Magnesite, containing a greater amount of magnesium over iron. Magnesite has perfect cleavage in three directions, which It is named after the presence of magnesium in its composition. Composition: Molecular Weight = 84.31 gm. This means that the recrystallization temperature is a decisive factor. Alloy Guide. Magnesium. It is in the autoclave that sand and lime react chemically and form a chemical compound, calcium-silicate. However, tantalite has a much greater specific gravity than columbite (8.0+ compared to columbite's 5.2). SiO2) Chrome ore which is a spinal the formula FeO Cr2O3. White, odorless, crystalline Because there is a general link between hardness and chemical composition, these generalizations can be made:. Magnesite is a magnesium carbonate with the same crystal structure as calcite, a calcium carbonate with a hardness and texture similar to White Magnesite and marble. Bauxite is a sedimentary rock with a relatively high aluminium content. It is also essential for proper heart function. AZ91. Magnesium is an electrolyte found in our bodies that plays a key role in muscle contraction. The sand-lime bricks taken out from the autoclave are ready for use. Some famous localities include The Lizard Peninsula, Cornwall, England (the type locality of Lizardite; the Antigorio Valley, Piedmont, Italy (the type locality of Antigorite); and Mount Olympus, Cyprus.The Jeffery Asbestos Mine in Richmond Co., Quebec, is the one of the most productive asbestos The properties of a high-quality low-iron type of magnesite are summarized in Table 1.It will be seen that the MgO content is 96%, the CaO/SiO 2 ratio about 2:1 and the porosity in the range Magnesium. Smithsonite. 1. AM60. To evaluate the toxicity, chemical properties and release of calcium and magnesium ions about 4 samples of DMT: Bioficina - DMT I, Flora Pinhais - DMT II, It is named after the presence of magnesium in its composition. Magnesite is a mineral with the chemical formula Mg C O 3 (magnesium carbonate). They can be dyed a turquoise blue color that makes them look very similar to natural turquoise. Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms.Weathering occurs in situ (on site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Non-flammable and non-combustible. Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts. In a few minutes he obtained a Decomposition of Magnesium Carbonate. Bornite is an important copper ore mineral and occurs widely in porphyry copper deposits along with the more common chalcopyrite. The global Magnesite market was valued at $7.4 billion in 2017. Minerals commonly associated with talc are tremolite (CaMg3 (SiO3)4), serpentine (2MgO.2SiO2.2HsO), anthophyllite (Mg7. Most sulfides are relatively soft (H < 5), with marcasite and pyrite being examples of exceptions (H < 6 to 6.5). Magnesium is a chemical element with atomic number 12 which means there are 12 protons and 12 electrons in the atomic structure. Imitation Opal is man-made and looks like opal, but without the same composition or structure. 24h Delivery. As can be seen in Table 1, the single-magnesite sample contained 47.20% MgO and the MgCO 3 content was 98.90%. Magnesite. Magnesite is a magnesium carbonate mineral with MgCO3 as its chemical composition. National Institutes of Health. The chemical reaction can be written as follows. Chemical Formula: MgFe+++2O4. Speaking of the primary raw materials applied in making the glass fibers, these include soda ash, limestone, and silica sand. Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places. Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts. Total number of protons in the nucleus is What is the nature of magnesium nitride? MgO has an extremely high melting temperature, and that makes it a good refractory material in many steelmaking, metallurgical, and ceramic processes. Choose: Choose: Choose: Custom Logo Add logos to all protected items: Custom creator profile A public list that shows all the items a creator/owner has in DMCA system: Digital Ink Signature Sign with your mobile, tablet, finger, mouse, touchpad etc. It will aid the development of psychic visions of exceptional clarity. ; Help desk Ask questions Use this stone for muscle relaxation, healthy evacuation of the large intestine and ease absorption and digestion of food. Magnesium is best absorbed when it is absorbed in small quantities over a long period of time (up to 12 hours). Prepackaged 1.7v Magnesium Anode With Gypsum Bentonite Sodium Sulphate Backfill Yx-mg-b48d5 , Find Complete Details about Prepackaged 1.7v Magnesium Anode With Gypsum Bentonite Sodium Sulphate Backfill Yx-mg-b48d5,Magnesium Sacrificial Anodes Oil Tank Sacrificial Anode,Magnesium Anodes Anode Sacrificial Marine Sacrificial Anodes,Sacrificial @inproceedings{1993MagnesiumcontainingMC, title={Magnesium-containing metal chemical conversion solution for composition, method of chemical conversion treatment, and chemical treatment material}, author={ and and }, year={1993} } , , ; Published 29 October 1993 Magnesite is a mineral that is composed of magnesium carbonate (MgCO3) and belongs to the calcite group of carbonate minerals. The mineral formed as a result of the action of magnesium-containing solutions on calcite or as an alteration product from magnesium-rich rocks. The chemical properties of Magnesium Carbonate are explained below: 1. 1. Basic oxygen steelmaking. Its compounds are widely used in construction Chemical composition analysis of magnesite. Magnesite Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure.The chemical symbol for Hydrogen is H. With a standard atomic weight of circa 1.008, hydrogen is the lightest element on the periodic table. General Magnesite Information. The chemical equation for the reaction can be given as, Chemical Properties of Magnetite Chemical Classification Oxide minerals Chemical Composition iron (II,III) oxide, Fe2+Fe3+2O4 Lime is a calcium-containing inorganic mineral composed primarily of oxides, and hydroxide, usually calcium oxide and/or calcium hydroxide.It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts. In the presence of CO 2, E was increased to 234 kJ mole 1 but was reduced slightly on the addition of ZnO or NiO. DIN. The melting point is 1500 C and above this temperature decomposes to form nitrogen gas. Most hydrous minerals are relatively soft (H < 5). Magnesite is a strong stone for creative visualization and imagination. Log In Register. Magnesite has a chemical composition of MgCO 3, and when it is heated it will dissociate into MgO and CO 2. Community portal The central hub for editors, with resources, links, tasks, and announcements. Magnetite crystals from Bolivia, 10 cm wide. Lithium shows similarities to magnesium in its chemical behaviour because of similar size, same electronegativity and similar high polarizing power. In fact, in 1855, before working with magnesium compounds, Stanislas Sorel first developed a two-component cement by mixing zinc oxide powder with a solution of zinc chloride. Reaction of magnesium with air. One of the worlds best Magnesite deposit occur in the State. Chemical Identification Chemical Identification CAS # 546-93-0; 13717-00-5 Formula MgCO. Magnesite is a magnesium carbonate mineral with a chemical composition of MgCO 3. It is named after the presence of magnesium in its composition. Magnesite usually forms during the alteration of magnesium-rich rocks or carbonate rocks by metamorphism or chemical weathering. Magnesite is used to produce magnesium oxide (MgO), Hydromagnesite was removed by reacting the bulk sediment with diluted acetic acid (10 vol%) for ~30 min. The major deposits occur in Chalk Hills of Salem district. Presents a detailed study of gemological properties, inclusion features, spectroscopic characteristics, and chemical composition of emeralds from this important source. Fig 4: Magnesia/Base Fire Bricks. The invention discloses a magnesite standard sample for chemical analysis and a preparation method thereof, and belongs to the technical field of metallurgical analysis. Alloy Tester Home ; Alloy Guide; Bruker S1 Titan . Chemical pulping involves dissolving lignin in order to extract the cellulose from the wood fiber. Magnesium element of the periodic system of chemical elements D. I. Mendeleev, with atomic number 12. Its chemical formula is (Mg,Fe)CO3. Properties. What is magnesium nitride used for? Our natural magnesium carbonate products (also called crude or raw magnesite) are of cryptocrystalline form, exhibiting extremely low amounts of Fe and Mn dissolved in their Gaspite-Magnesite Series and Magnesite-Siderite Series. Chemical element, Magnesium, information from authoritative sources. The magnesite dust was added into the hydrochloric acid solution of 200 ml and stirred at a stirring speed of 500 rpm using Remi stirrer with motor (Model No. Serpentine group minerals antigorite, lizardite, and chrysotile are produced by the hydrous alteration of ultramafic rocks. It is a major source of magnesium. Magnesium 12.15 % Mg 20.15 % MgO. There are varieties of hydrate containing crystal water, those seen often are anhydride, It occurs in a range of green, yellowish green, yellowish brown and slightly bluish green colors. X-ray diffraction pattern of the magnesite sample. (OH)2. For magnesite, the most reliable fractionation factor() equation is given as: The chemical formulas of asbestos minerals are idealized. Mg 12 Magnesium . ; Site news Sources of news about Wikipedia and the broader Wikimedia movement. Admixture with CaO reduced the value of E to 54 kJ mole 1. markers, slabs and tiles after cutting and polishing. Chemical Composition: CuAl 6 (PO 4) 4 Howlite and magnesite are light gray to white minerals that often have markings that resemble the spider webbing seen in some turquoise. Chemical PAC-1 PAC-2 PAC-3; Magnesium carbonate; (Magnesite) (546-93-0) 45 mg/m3 : 260 mg/m3 : 1600 mg/m3 The International Mineralogical Association recognizes lime as a mineral with the chemical formula More than half the worlds steel is produced in the basic oxygen process (BOP), which uses pure oxygen to convert a charge of liquid blast-furnace iron and scrap into steel. Magnetite is a mineral whose primary component is an iron oxide that contains equal amounts of iron (II) and iron (III). Transcribed image text: Magnesite is a magnesium carbonate mineral with a chemical composition of MgCO3. Magnesium nitrate is an inorganic hygroscopic salt, which is composed of magnesium, nitrogen and oxygen with the chemical formula Mg (NO3)2. Natural magnesite belongs to trigonal crystal or cryptocrystalline white magnesium carbonate. Serpentine is a very common mineral, and is found in abundance worldwide. So it is characterized by the following chemical reactions: 1. the reaction of magnesium oxide with hydrogen: MgO + H2 Mg + H2O. Its density is 2.71 g mL-1. Composition: Molecular Weight = 200.00 gm. Magnesite has the same structure as other members of the calcite group. IMA Formula: Mg(CO 3) Elements listed: C, Mg, O - search Magnesite is a mineral with the chemical formula MgCO 3 (magnesium carbonate). Synonyms carbonate magnesium; hydromagnesite; magnesium carbonate; Physical properties. The dolomite (DMT) can affect the metabolism of calcium and hydroxyl ions mineralization. Introduction. Magnesite contains a high level of magnesium and aids its absorption in the body. Protons and Neutrons in Magnesium. Figure 1 . Oxygen When ingited, Mg reacts with both oxygen and nitrogen forming a mixture of magnesium oxide, MgO, and magnesium nitride, Mg 3 The most common chemical elements in the crust are oxygen (46.6%), silicon (27.7), aluminum (8.1), iron (5.0), calcium (3.6), potassium (2.8), sodium (2.6), and magnesium (2.1). National Library of Medicine. Properties Magnesite refractories essentially have periclase (crystalline megnesia) in a metrix of foresterite (2MgO. Magnesite can form a 3.1.2 Other Group IIA carbonates. Magnesium 28.83 % Mg 47.80 % MgO. The Magnesite crystal stone is one of a kind among healing crystals. The raw magnesite used was the type KERMA with low iron, supplied by Grecian Magnesite having the characteristics presented in Table 3. Sorel cement (also known as magnesia cement or magnesium oxychloride) is a non-hydraulic cement first produced by the French chemist Stanislas Sorel in 1867.. Magnesium Fluoride is used to treat various health issues. Magnetite. IDM H&S committee meetings for 2022 will be held via Microsoft Teams on the following Tuesdays at 12h30-13h30: 8 February 2022; 31 May 2022; 2 August 2022 Magnesite is a white mineral that is often dyed to imitate turquoise or dyed outrageous colors for fun. Manganese also substitutes for magnesium, but typically only to the extent of a few percent and in most cases only along with iron. Magnesium sulfate or magnesium sulphate (in English-speaking countries other than the US) is a chemical compound, a salt with the formula MgSO4, consisting of magnesium cations Mg2+ (20.19% by mass) and sulfate anions SO24. AISI. Magnesite is a natural ore composed almost entirely of MgCO3, and its theoretical chemical composition is MgO447.82%, CO252.18%. The latter is a talclike mineral in which varying proportions of aluminium are substituted for magnesium in the brucite layer. The magnesium isotope composition of solid and fluid samples was determined following the method described in Mavromatis et al.