Crystal structures considered as being “essentially the same” can be denoted by the term homeotypic. elements with similar crystal-chemical behavior). isotypic structure belonging to one structural type) and composed of chemically similar elements (i.e. ( Dana classification,) or as phosphates, arsenates and vanadates with additional anions without water ( Strunz classification 4Ī mineral group consists of two or more minerals with the same or essentially the same structure (i.e. The variable formula should be written as: (Ca,Sr,Pb,Y,Mn,Na) 5(PO 4,AsO 4,SO 4CO 3) 3(F,Cl,OH).:
are classified as hexagonal or pseudohexagonal monoclinic anhydrous phosphates containing hydroxyl or halogen of the generic formula 3
The mineral classification system developed by German mineralogist K.H.
Biogenic substancescan be accepted as minerals if geological processes were involved in the genesis of these compounds ., from the apatite group 2 If the synthetic substance has a simple formula, then the preference should be given to the use of a chemical formula instead of a mineral name. If such substances are identical to minerals, they can be referred as the “synthetic equivalents” of given mineral. Anthropogenic substancesare not considered as minerals. Mineraloidsare mineral-like phases including synthetic materials, human-treated substances, and some biological materials, which do not fulfill the criteria for the definition of mineral species. The total number of minerals accepted by mineralogical community is about 4000. Mineralsare individual components comprising rocks formed by geological processes classified according to their crystal structure and chemical composition.
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