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During active carbonatogenesis, the carbonate particles are produced by ionic exchanges through the cell membrane [32] by activation of calcium and/or magnesium ionic pumps or channels, probably coupled with carbonate ion production. [31] During passive carbonatogenesis, two metabolic cycles can be involved, the nitrogen cycle and the sulfur cycle.
Magnesium carbonate is ordinarily obtained by mining the mineral magnesite. Seventy percent of the world's supply is mined and prepared in China. [9] Magnesium carbonate can be prepared in laboratory by reaction between any soluble magnesium salt and sodium bicarbonate: MgCl 2 (aq) + 2 NaHCO 3 (aq) → MgCO 3 (s) + 2 NaCl(aq) + H 2 O(l) + CO 2 (g)
The biogenic formation of calcium carbonate structures is the result of a combination of biological and physical processes such as genetics, cellular activity, crystal competition, growth in confined spaces, and self-organization processes. The composition of these structures, and the mechanisms involved in building them, are highly diverse.
Magnesium oxide is the end product of the thermal decomposition of some magnesium compounds and is usually prepared by igniting carbonates or hydroxides. Magnesium hydroxide is a strong electrolyte, which can be obtained by the reaction of a soluble magnesium salt and sodium hydroxide.
Magnesite can also be formed via the carbonation of magnesium serpentine (lizardite) via the following reaction: 2 Mg 3 Si 2 O 5 (OH) 4 + 3 CO 2 → Mg 3 Si 4 O 10 (OH) 2 + 3 MgCO 3 + 3 H 2 O. However, when performing this reaction in the laboratory, the trihydrated form of magnesium carbonate (nesquehonite) will form at room temperature. [6]
Fossil skeletal parts from extinct belemnite cephalopods of the Jurassic – these contain mineralized calcite and aragonite.. Biomineralization, also written biomineralisation, is the process by which living organisms produce minerals, [a] often resulting in hardened or stiffened mineralized tissues.
The mechanisms of mineral deposition within the organic portion of the bone are still under investigation. Three possible suggestions are that nucleation is either due to the precipitation of calcium phosphate solution, caused by the removal of biological inhibitors or occurs because of the interaction of calcium-binding proteins.
Magnesium can also be toxic to plants, although this is typically seen only in drought conditions. [47] [48] Space-filling model of the chlorophyll a molecule, with the magnesium ion (bright-green) visible at the center of the chlorin group. In animals, magnesium deficiency (hypomagnesemia) is seen when the environmental availability of ...